The RadioMaster ER5A ExpressLRS PWM Receiver w/ Spare Long Antenna features a compact size and is easy to install. It's perfect for surface, marine, and air R/C applications. The ER5A supports 8.4V HV servos and accessories, and a robust injection-molded receiver casing. It has fast response speeds and incredible range. The RadioMaster ER5A Receiver supports 4 proportional and 1 switch channel (ExpressLRS 2.x) or 5 proportional channels (ExpressLRS 3.x).