4PK 2.4GHz FASST R604FS Futaba's FASST (Futaba Advanced Spread Spectrum Technology) shifts very quickly virtually eliminating signal conficts and interruptions unlike other 2.4GHz systems that only stay on one or two frequencies Dual antenna diversity enables FASST system to automatically and seamlessly select the best reception between the two antenna built into the receiver ensuring that model stays under constant control of transmitter regardless of altitude Pre-Vision Packet Screening technology scans incoming data