... stroke servo 3. Easy operation, prompt response and fine travel control Name: (9035-1) 4CH 2.4G rc helicopter NEW! HOT ... . Fatures light weight, easy operation, prompt response and fine travel control;2. Function: Roll left/ right, flying Up, down, forward, backward ... and Precise;5. Anybody can fly well;6. Built in Gyroscope;7. Lightweight Design , Portable, Easy and High Safety on Operation ...