HK-450 CCPM 3D Helicopter Kit Modeled on the famous and proven T-Rex 450. Spec: Length:660mm Height:230mm Main Blade Length:325mm Main Rotor Diameter:700mm Tail Rotor Diameter:150mm Motor Pinion Gear:12T/13T (Not included) Main Drive Gear:150T Autorotation Tail Drive Gear:106T Tail Drive Gear:25T Weight(w/o blade):450g Flying Weight:730~760g Upgraded belt pulley gear & shaft. (No-slippage) Required items. Brushless Outrunner Motor & Pinion Gear Servos Gyro Receiver ESC Lipoly Battery (2200mAh 3S)