RadioMaster ERS-RC01 - CDI Gas Engine Tachometer for Compatible ExpressLRS PWM ReceiversThe ERS RC01 Gasoline Engine Tachometer measures RPM by connecting directly to your engine's CDI speed output. The sensor accurately detects engine speed, transmits the data to a compatible ExpressLRS receiver through the CRSF interface, and then sends it back to your EdgeTX radio for real time monitoring. Ideal for any application requiring accurate RPM feedback. As part of the ERS sensor family, the ERS RC01 also supports pass through expansion,