The RB-OA3R is a 1U rack mount switch unit for use in each studio that needs to be connected to the STUDIO 1-3 CONTROL connectors on an RB-OA3. It takes its power from the RB-OA3 unit so needs no power supply itself.
It contains four buttons which are used to control the functions of the RB-OA3. Each front panel push button is illuminated by coloured LEDs and controls the OFFER, ACCEPT, DELAY and DUMP functions.