From Lectrosonics, the RM Remote Control unit is a simple and effective way to change parameter settings on SM series transmitters remotely. The remote features a built-in speaker that produces a "dweedle" tone.
The remote's parameters are synchronized with SM series transmitters when the tone is produced through the transmitter's lavalier microphone. The RM remote is a useful for device producers in broadcast and performance applications, where it is impractical for the talent to access the transmitter in order to change parameters.