Shure GLXD14/PG30 Digital Headset Wireless System with PG30 Headset Microphone, Z2 Includes: (1) GLXD4 Wireless Receiver, (1) GLXD1 Wireless Bodypack Transmitter, (1) PG30TQG Condenser Headworn Microphone (with windscreen), (1) PS42US Power Supply, (1) SB902 Rechargeable Lithium-Ion Battery, (1) USB Charge Cable and (1) Carrying Case Operate up to 4 compatible systems in typical setting, up to 8 maximum under ideal conditions Best-in-class intelligent lithium-ion battery rechargeability allows up to 16 hours of continuous use and greatly reduces the cost of ownership LINKFREQ Automatic Frequency Management Intelligent frequency management quickly identifies the best open frequencies