The Electro-Voice RE3-BPTRSB-6M is a compact, lightweight UHF bodypack transmitter specifically modified to work exclusively with the RSB-2 Referee Switch Box. Designed for sports officiating, it features a durable all-metal housing that is easy to wear and conceal while standing up to demanding use. The transmitter uses ultrasonic sync to transfer frequency and functional settings from the receiver for quick and easy setup. Selectable RF output power of 10 or 20 mW helps accommodate different transmission range requirements. Its magnetic sliding latch and locking mechanism provide secure battery access, while built-in charging contacts support the optional BC2 charging station for compatible NiMH rechargeable batteries. Operating in the 653–663 MHz frequency band, the RE3-BPTRSB-6M offers a 10 MHz tuning bandwidth and 400 selectable frequencies. It operates on two AA alkaline or rechargeable NiMH batteries and features a 4-pin mini input jack for connection to the RSB-2 Referee Switch Box.