The Electro-Voice RE3-BPKRSB-6M is a UHF wireless bodypack system configured for use with the RSB-2 Referee Switch. It features the rugged metal RE3-BPTRSB bodypack transmitter, designed to work exclusively with the RSB-2, and an RE3-RX diversity receiver. The compact transmitter can be worn and concealed under a uniform, making the system suitable for sports officiating applications. It uses ultrasonic synchronization for quick transmitter-to-receiver setup and offers selectable RF output power for different transmission range requirements. Operating in the 653–663 MHz frequency band, the system provides a 10 MHz tuning bandwidth, 400 selectable frequencies, and transmitter output power options of 10 or 20 mW.