RadioMaster ER3Ci 2.4GHz ELRS PWM Surface Receiver with Built in AntennaThe RadioMaster ER3C i receiver is based on the high performance, revolutionary ExpressLRS system, featuring high reliability, highly flexible configuration, ultra fast response speeds, and an ultra long receiving range, bringing with it a brand new usage experience. The ER3C i ELRS receiver can drive up to 3 servos and has built in receiver voltage telemetry and battery telemetry with the ability to automatically detect which voltage input to use.