Shure SBC441 - 4-Bay Docking Station for Axient Digital PSMPower supply sold separately, for acting as a secondary unit to another SBC441. The SBC441 4 Bay Docking Charger supports up to four Axient Digital ADXR Wireless Bodypack Receivers or Shure SB910 rechargeable batteries. The SBC441 includes dual network ports for monitoring and network pass through. Compatible with both Shure SB910 rechargeable batteries and Axient Digital PSM ADXR bodypack receivers, the SBC441 desktop networked charger is a great