The Sennheiser BA 50-2 is a small rechargeable battery pack for 3000/5000 Series bodypack wireless transmitters. It holds two AA NiCd rechargeable batteries and is compatible with the SK 50 and SK 3063 transmitters.
The BA 50-2 is also suitable for the EK 3041 receiver when used with the GA 3041-B battery adapter (available separately).