SHURE, beta58

Shure SLXD24/B58 Wireless System with Beta 58A Handheld Transmitter SLXD Series Wireless System with Beta58 Handheld Transmitter and SLXD4 Wireless Receiver
  Shure SLXD24/B58 Wireless System with Beta 58A Handheld Transmitter 

The SLXD24/B58 Wireless System delivers transparent, 24-bit digital audio and rock-solid RF performance for a wide range of

Shure SLXD24D/B58 Digital Wireless Dual Handheld Microphone System SLXD Series Wireless System with 2 Beta58 Handheld Transmitters and SLXD4D Wireless Receiver
  Shure SLXD24D/B58 Digital Wireless Dual Handheld Microphone System 

The Beta58, from Shure, has become a live sound staple since its release in 1989.

Shure QLXD24/BETA58 Handheld Wireless Microphone System, QLXD4 Receiver & QLXD2/BETA58A Handheld Transmitter BETA 58A, QLXD4, microphone clip, power supply, 2 AA batteries, battery contact cover, two 1/2 wave antennas, 2 BNC cables, zipper bag, 2 BNC bulkhead adapters, rackmount kit, and user guide
  SPECIFICATIONS Simultaneous