The BCA42 is a battery power supply module that provides portable operation for compatible Wisycom wireless gear by delivering power from five 1.5 V AA cells. Batteries are included. The unit must be installed together with a BPA42PTT or BPA42HPN to enable operation and battery switching. It does not process audio or RF signals and functions solely as a power accessory within the MCR41S-42S system, providing a compact, field-ready power solution for beltpack and receiver setups.