Electro-Voice / Telex RSB-2 - Referee Switch for EV or Telex Wireless SystemsThe RSB 2 toggle mute switch is the football standard for referee wireless systems. The RSB 2 plugs in between the lavalier or headworn microphone and the bodypack transmitter to provide a noiseless mute. The REV WT and WTU 2 bodypacks automatically recognize the RSB 2 but older transmitters require a special referee version. Features: TA4 in and out connectors for any EV Telex lavalier microphone and bodypack transmitter Belt clip for wearing on