Feature Highlights: ? Ergonomically designed for optimal hand grip to prevent slippage, light weight, and easy to assemble/disassemble for transport ease. Suitable for fixed wing airplanes or helicopters, engine can be started with a simple one hand press on the button. ? Suitable for up to 50cc gasoline engine or 300 class nitro engine. ? Designed for user replaceable, common 450 heli sized 3S1P 1900~2300mAh/16c lipo batteries. Fully charged battery is capable of 500 starts and beyond. Battery packs are charged with any T-REX 450 battery chargers. ? Starting adaptor includes double one way bearing design. ? High efficiency motor providing high starting power, and low reacting force. ? LED battery voltage indicator and over-discharge protection circuitry. ? Battery undervoltage protection. ? Overheating protection ? Protection against stalling by flooded torque overloading engine.