Futaba R603FF 3-Channel FASST 2.4GHz Receiver (Rx) for 3PM, 3PK, 4PK Incredibly small and lightweight For use with the Futaba 3PM, 3PK, and 4PK systems FASST allows the receiver to process information at eight times the resolution of standard systems for unsurpassed control and smooth servo travel One year limited waranty