diff --git a/src/Enums/NBT/AttributeOperation.enum.js b/src/Enums/NBT/AttributeOperation.enum.js
new file mode 100644
index 0000000..0399044
--- /dev/null
+++ b/src/Enums/NBT/AttributeOperation.enum.js
@@ -0,0 +1,6 @@
+
+module.exports = Object.freeze({
+  ADD: 0,
+  MULTIPLY_BASE: 1,
+  MULTIPLY: 2
+});
diff --git a/src/Enums/NBT/BookGeneration.enum.js b/src/Enums/NBT/BookGeneration.enum.js
new file mode 100644
index 0000000..0446651
--- /dev/null
+++ b/src/Enums/NBT/BookGeneration.enum.js
@@ -0,0 +1,7 @@
+
+module.exports = Object.freeze({
+  ORIGINAL: 0,
+  COPY: 1,
+  COPY_OF_COPY: 2,
+  TATTERED: 3
+});
diff --git a/src/Enums/NBT/CollarColor.enum.js b/src/Enums/NBT/CollarColor.enum.js
new file mode 100644
index 0000000..3c6449e
--- /dev/null
+++ b/src/Enums/NBT/CollarColor.enum.js
@@ -0,0 +1,19 @@
+
+module.exports = Object.freeze({
+  WHITE: 0,
+  ORANGE: 1,
+  MAGENTA: 2,
+  LIGHT_BLUE: 3,
+  YELLOW: 4,
+  LIME: 5,
+  PINK: 6,
+  GRAY: 7,
+  LIGHT_GRAY: 8,
+  CYAN: 9,
+  PURPLE: 10,
+  BLUE: 11,
+  BROWN: 12,
+  GREEN: 13,
+  RED: 14,
+  BLACK: 15
+});
diff --git a/src/Enums/NBT/ExplosionType.enum.js b/src/Enums/NBT/ExplosionType.enum.js
new file mode 100644
index 0000000..a1edbb1
--- /dev/null
+++ b/src/Enums/NBT/ExplosionType.enum.js
@@ -0,0 +1,13 @@
+
+/**
+  * The type of firework explosions
+  * UNKNOWN_SHAPE will be rendered as small ball and named as Unknown Shape
+  */
+module.exports = Object.freeze({
+  SMALL_BALL: 0,
+  LARGE_BALL: 1,
+  STAR_SHAPE: 2,
+  CREEPER_SHAPE: 3,
+  BURST: 4,
+  UNKNOWN_SHAPE: 5
+});
diff --git a/src/modules/Manager/WindowManager.class.js b/src/modules/Manager/WindowManager.class.js
new file mode 100644
index 0000000..93e62f5
--- /dev/null
+++ b/src/modules/Manager/WindowManager.class.js
@@ -0,0 +1,86 @@
+const Manager = require("./Manager.class.js");
+const WindowPackageHandler = require("../../Packages/PackageHandler/Player/WindowPackageHandler.class.js");
+
+class WindowManager extends Manager {
+  constructor() {
+      super();
+  }
+
+  /**
+   * addWindow - add a new window to manager
+   *
+   * @param {Window} window The window
+   *
+   * @return {type} Description
+   */
+  addWindow(window) {
+    this.addObject(window.id, window);
+  }
+
+
+  /**
+   * removeWindow - remove a window from list
+   *
+   * @param {Window} window The window to remove
+   *
+   * @return {type} Description
+   */
+  removeWindow(window) {
+    this.removeObject(window.id);
+  }
+
+
+  /**
+   * removeWindowById - Remove a specific window by id
+   *
+   * @param {number} id the window id
+   *
+   * @return {type} Description
+   */
+  removeWindowById(id) {
+    this.removeObject(id);
+  }
+
+
+  /**
+   * getWindow - get a window by id
+   *
+   * @param {number} id The window id
+   *
+   * @return {Window} return the window
+   */
+  getWindow(id) {
+    this.getObject(id);
+  }
+
+
+  /**
+   * getAllWindows - Get a list with all windows
+   *
+   * @return {array} A list with all windows
+   */
+  getAllWindows() {
+    return this.getAllObjects();
+  }
+
+
+  /**
+   * createWindow - create a new window
+   *
+   * @param {Player}     player   The owner player
+   * @param {number}     size     The count of window slots
+   * @param {Entity}     entity   the entity
+   * @param {WindowType} type     the window type
+   * @param {string}     [title=] custom window title
+   * @param {number}     [id]     The window id
+   *
+   * @return {type} Description
+   */
+  createWindow(player, size, entity, type, title = "", id = this.getAllWindows().length) {
+    let window = new WindowPackageHandler(player, id, size, entity, type, title);
+    this.addWindow(window);
+    return window;
+  }
+}
+
+module.exports = WindowManager;
diff --git a/src/modules/Model/Color.class.js b/src/modules/Model/Color.class.js
new file mode 100644
index 0000000..c2f000e
--- /dev/null
+++ b/src/modules/Model/Color.class.js
@@ -0,0 +1,25 @@
+
+/**
+ *
+ */
+class Color {
+
+  /**
+   * constructor - Init Color
+   */
+  constructor() {
+    this.red = 0;
+    this.green = 0;
+    this.blue = 0;
+  }
+
+
+  /**
+   * getColorCode - Return a color code for NBT data
+   *
+   * @return integer
+   */
+  getColorCode() {
+    return (this.red << 16) + (this.green << 8) + this.blue;
+  }
+}
diff --git a/src/modules/Model/NBT/ItemStructure.class.js b/src/modules/Model/NBT/ItemStructure.class.js
new file mode 100644
index 0000000..3fc5621
--- /dev/null
+++ b/src/modules/Model/NBT/ItemStructure.class.js
@@ -0,0 +1,478 @@
+const {ServerError, NBTNumberNotInRangeError} = require("../../Utils/ServerError.class.js");
+
+/**
+  * VERSION SUPPORT: 1.8 -> ?
+  */
+class ItemStructure {
+  constructor() {
+    // Init General
+    this.general = [];
+    this.general.damage = null;
+    this.general.unbreakable = null;
+    this.general.canDestroy = null;
+    this.general.customModelData = null;
+
+    // Block Tags
+    this.block = [];
+    this.block.canPlaceOn = null;
+    this.block.blockEntityTag = null;
+    this.block.blockStateTag = null;
+
+    // Enchantments
+    this.enchantments = [];
+    this.storedEnchantments = [];
+    this.repairCost = null;
+
+    // Attribute Modifiers
+    this.attributes = [];
+
+    // potion effect
+    this.potionEffects = [];
+    this.potion = null;
+
+    // TODO: Crossbow
+
+    // Display
+    this.display = [];
+    this.display.display = [];
+    this.display.display.color = null;
+    this.display.display.name = null;
+    this.display.display.lore = [];
+    this.display.hideFlags = null;
+
+    // Books
+    this.resolved = null;
+    this.generation = null;
+    this.author = null;
+    this.title = null;
+    this.pages = [];
+
+    // Player Head
+    this.skullOwner = [];
+    this.skullOwner.id = null;
+    this.skullOwner.name = null;
+    this.skullOwner.properties = [];
+    this.skullOwner.properties.texture = null;
+
+    // Fireworks
+    this.fireworks = [];
+    this.fireworks.flight = null;
+    this.fireworks.explosions = null;
+
+    // Firework Star
+    this.explosion = [];
+    this.explosion.flicker = null;
+    this.explosion.trail = null;
+    this.explosion.type = null;
+    this.explosion.colors = [];
+    this.explosion.fadeColors = [];
+
+  }
+
+  /**
+   * createEnchantment - Create a new Item Enchantment
+   *
+   * @param  string id The enchantment id
+   * @param  int level The level of enchantment
+   */
+  createEnchantment(id, level) {
+    this.enchantments.push({id: {type: 'short', value: id}, lvl: {type: 'short', value: level}});
+  }
+
+
+  /**
+   * createStoredEnchantment - Create a enchantment for books
+   *
+   * @param  int id    the enchantment id
+   * @param  int level the level of enchantment
+   */
+  createStoredEnchantment(id, level) {
+    this.storedEnchantments.push({id: {type: 'string', value: id}, lvl: {type: 'short', value: level}});
+  }
+
+
+  /**
+   * createAttribute - Create a new attribute modifier to modifier item
+   *
+   * @param  string attributeName the name of attribute
+   * @param  string name          the name of modifier (has no effect)
+   * @param  string slot          the slot to take a effect ("mainhand", "offhand", "feet", "legs", "chest", "head")
+   * @param  int operation        modifier operation (add [id=0], multiply_base [id=1], multiply [id=2])
+   * @param  double amount        the amount of change
+   * @param  long uuidMost        uppermost bits of the modifier's UUID
+   * @param  long uuidLeast       lowermost bits of the modifier's UUID
+   */
+  createAttribute(attributeName, name, slot, operation, amount, uuidMost, uuidLeast) {
+    this.attributes.push({AttributeName: {type: 'string', value: attributeName}, Name: {type: 'string', value: name}, Slot: {type: 'string', value: slot}, Operation: {type: 'int', value: operation}, Amount: {type: 'double', value: amount}, UUIDMost: {type: 'long', value: uuidMost}, UUIDLeast: {type: 'long', value: uuidLeast}});
+  }
+
+
+  createTexture(url, options = {}) {
+    let cacheTextureData = {};
+    if(options.timestamp !== undefined){
+      cacheTextureData.timestamp = {
+        type: "long",
+        value: options.timestamp
+      }
+    }
+
+    if(options.profileId !== undefined){
+      cacheTextureData.profileId = {
+        type: "string",
+        value: options.profileId
+      }
+    }
+
+    if(options.profileName !== undefined){
+      cacheTextureData.profileName = {
+        type: "string",
+        value: options.profileName
+      }
+    }
+
+    if(options.isPublic !== undefined){
+      cacheTextureData.isPublic = {
+        type: "string",
+        value: options.isPublic
+      }
+    }
+
+    cacheTextureData.textures = {
+      type: "compound",
+      value: {
+        SKIN: {
+          type: "compound",
+          value: {
+            url: {
+              type: "string",
+              value: url
+            }
+          }
+        }
+      }
+    }
+
+    let cacheTexture = {type: "compound", value: {}};
+    cacheTexture.value.Value = {type: "string", value: Buffer.from(JSON.stringify(cacheTextureData)).toString("base64")};
+
+    if(options.signature !== undefined) {
+      cacheTexture.value.Signature = {type: "String", value: options.signature};
+    }
+
+    //this.skullOwner.properties.texture = cacheTexture;
+  }
+
+  /**
+   * createPotionEffect - Create a new Potion effect
+   *
+   * @param  byte id               id of effect
+   * @param  byte amplifier        amplifier of the effect
+   * @param  int duration          duration of effect in ticks
+   * @param  boolean ambient       if this effect a bacon effect
+   * @param  boolean showParticles produces particles
+   */
+  createPotionEffect(id, amplifier, duration, ambient, showParticles) {
+    this.potionEffects.push({Id: {type: 'byte', value: id}, Amplifier: {type: 'byte', value: amplifier}, Duration: {type: 'int', value: duration}, Ambient: {type: 'byte', value: boolToNum(ambient)}, ShowParticles: {type: 'byte', value: boolToNum(showParticles)}});
+  }
+
+
+  /**
+   * getNBT - Get the NBT raw data from item structure
+   *
+   * @return JSON The json NBT data structure
+   */
+  getNBT() {
+    let data = {
+      type: "compound",
+      name: "",
+      value: {}
+    };
+
+    // Set general data
+    /*
+    > 1.8
+    if(this.general.damage !== null) {
+      data.value.Damage = {
+        type: "short",
+        value: this.general.damage
+      }
+    }
+    */
+
+    if(this.general.unbreakable !== null) {
+      data.value.Unbreakable = {
+        type: "byte",
+        value: boolToNum(this.general.unbreakable)
+      }
+    }
+
+    if(this.general.canDestroy !== null) {
+      data.value.CanDestroy = {
+        type: "list",
+        value: {
+          type: "string",
+          value: this.general.canDestroy
+        }
+      }
+    }
+
+    /*
+    > 1.8
+    if(this.general.customModelData !== null) {
+      data.value.CustomModelData = {
+        type: "int",
+        value: this.general.customModelData
+      }
+    }
+    */
+
+    if(this.block.canPlaceOn !== null) {
+      data.value.CanPlaceOn = {
+        type: "list",
+        value: {
+          type: "string",
+          value: this.general.canPlaceOn
+        }
+      }
+    }
+
+    // TODO: BlockEntityTag
+
+    // Enchantments
+    if(this.enchantments.length > 0) {
+      data.value.ench = {
+        type: "list",
+        value: {
+          type: "compound",
+          value: this.enchantments
+        }
+      }
+    }
+
+    if(this.storedEnchantments.length > 0) {
+      data.value.StoredEnchantments = {
+        type: "list",
+        value: {
+          type: "compound",
+          value: this.storedEnchantments
+        }
+      }
+    }
+
+    if(this.repairCost !== null) {
+      data.value.repairCost = {
+        type: "int",
+        value: this.repairCost
+      }
+    }
+
+
+    // Attribute Modifiers
+    if(this.attributes.length > 0) {
+      data.value.AttributeModifiers = {
+        type: "list",
+        value: {
+          type: "compound",
+          value: this.attributes
+        }
+      }
+    }
+
+
+    // Potion Effect
+    if(this.potionEffects.length > 0) {
+      data.value.CustomPotionEffects = {
+        type: "list",
+        value: {
+          type: "compound",
+          value: this.potionEffects
+        }
+      }
+    }
+
+    if(this.potion !== null) {
+      data.value.Potion = {
+        type: "string",
+        value: this.potion
+      }
+    }
+
+    // Set display data
+    let cacheData = this.getDisplayData();
+    if(cacheData !== null) {
+      data.value.display = cacheData;
+    }
+
+    // Set hide flags
+    if(this.display.hideFlags !== null) {
+      data.value.HideFlags = {
+        type: "int",
+        value: this.display.hideFlags
+      };
+    }
+
+
+    // Set Book Data
+    if(this.resolved) {
+      data.value.resolved = {
+        type: "byte",
+        value: 1
+      }
+    }
+
+    if(this.generation !== null) {
+      data.value.generation = {
+        type: "int",
+        value: this.generation
+      }
+    }
+
+    if(this.author !== null) {
+      data.value.author = {
+        type: "string",
+        value: this.author
+      }
+    }
+
+    if(this.title !== null) {
+      data.value.title = {
+        type: "string",
+        value: this.title
+      }
+    }
+
+    if(this.pages.length > 0) {
+      data.value.pages = {
+        type: "list",
+        value: {
+          type: "string",
+          value: this.pages
+        }
+      }
+    }
+
+    // Player Heads
+    /*if(this.skullOwner.id !== null && this.skullOwner.name !== null && this.skullOwner.properties.texture !== null) {
+      data.value.SkullOwner = {
+        type: "compound",
+        value: {
+          Id: {type: "string", value: this.skullOwner.id},
+          Name: {type: "string", value: this.skullOwner.name},
+          Properties: {
+            type: "compound",
+            value: {
+              textures: {
+                type: "list",
+                value: this.skullOwner.properties.texture
+              }
+            }
+          }
+        }
+      }
+    }*/
+
+    if(this.skullOwner.name !== null) {
+      data.value.SkullOwner = {
+        type: "compound",
+        value: {
+          Name: {type: "string", value: this.skullOwner.name}
+        }
+      }
+
+      if(this.skullOwner.id !== null) {
+        data.value.SkullOwner.value.Id = {type: "string", value: this.skullOwner.id};
+      }
+
+      if(this.skullOwner.properties.texture !== null) {
+        data.value.SkullOwner.value.Properties = {
+          type: "compound",
+          value: {
+            textures: {
+              type: "list",
+              value: this.skullOwner.properties.texture
+            }
+          }
+        };
+      }
+    }
+
+
+    if(this.fireworks.flight !== null) {
+      if(this.fireworks.flight < -128 || this.fireworks.flight > 127) {
+        throw new NBTNumberNotInRangeError(this.fireworks.flight, "-128", "127");
+        return;
+      }
+
+      data.value.Fireworks.type = "compound";
+      data.value.Fireworks.value.Flight = {};
+      data.value.Fireworks.value.Flight.type = "byte";
+      data.value.Fireworks.value.Flight.value = this.fireworks.flight;
+    }
+
+    if(this.fireworks.explosion !== null && this.fireworks.explosion.length > 0) {
+      // TODO
+    }
+
+    return data;
+  }
+
+  /**
+   * getDisplayData - Get the display NBT data
+   *
+   * @return JSON the NBT JSON data
+   */
+  getDisplayData() {
+    let displayData = {};
+    displayData.type = "compound";
+    displayData.value = {};
+
+    // Set color
+    if(this.display.display.color !== null) {
+      displayData.value.color = {
+        type: "int",
+        value: this.display.display.color
+      };
+    }
+
+    // Set name
+    if(this.display.display.name !== null) {
+      displayData.value.Name = {
+        type: "string",
+        value: this.display.display.name
+      };
+    }
+
+    // Set lore
+    if(this.display.display.lore.length > 0) {
+      displayData.value.Lore = {
+        type: "list",
+        value: {
+          type: "string",
+          value: this.display.display.lore
+        }
+      };
+    }
+
+    if(Object.keys(displayData.value) === 0) {
+      displayData = null;
+    }
+    return displayData;
+  }
+
+
+  /**
+   * boolToNum - Parse a boolean to a number
+   *
+   * @param  {type} bool description
+   * @return {type}      description
+   */
+  boolToNum(bool) {
+    if(bool) {
+      return 1;
+    }
+    return 0;
+  }
+}
+
+
+module.exports = ItemStructure;
diff --git a/src/modules/Utils/ServerError.class.js b/src/modules/Utils/ServerError.class.js
new file mode 100644
index 0000000..ffad239
--- /dev/null
+++ b/src/modules/Utils/ServerError.class.js
@@ -0,0 +1,19 @@
+class ServerError extends Error {
+  constructor(message) {
+    super(message);
+    this.name = this.constructor.name;
+    Error.captureStackTrace(this, this.constructor);
+  }
+}
+
+class NBTNumberNotInRangeError extends ServerError {
+  constructor(number, from, to) {
+    super("The number " + number + " is not in the range between " + from + " and " + to);
+    this.data = { number, from, to };
+  }
+}
+
+module.exports = {
+  ServerError,
+  NBTNumberNotInRangeError
+};