UHF PLL Stereo/Mono In Ear Monitor Single Receiver Body Pack for use with WMS-4T Transmitter.  EU-4 dynamic in-ear monitor headphones included.

Specs:

• 961 preset selectable channels
• Full LCD display with backlight
• Full metal case
• Lock-On function
• Built-in dynamic limiter
• Requires 2 AA batteries (not included)
• Frequency Range: 638 - 662 MHz