Shure BLX188/CVL Dual Channel Lavalier Wireless System with 2 CVL Lavalier Microphones, K12 Includes BLX88 dual-channel receiver, 2 BLX1 body pack transmitters, 2 CVL Lavalier microphones, Lavalier clip, windscreens, and user guide. Power and battery status LED Adjustable gain control Quick & easy frequency matching 300 feet (91 m) operating range (line of sight) Quick and easy receiver frequency matching, easily accessible On / Off switch TQG connection for use with Shure lavalier, headset, earset and instrument mics and guitar cables Up to 14 hours of continuous use with 2 AA batteries (included), plus power and battery status LED 300 ft (100 m) operating range (line of sight) Up to 12 compatible systems per frequency band (region dependent), plus One-touch QuickScan frequency selection quickly locates the best frequency. XLR and &#034; output connectors. Two-color audio status indicator LED (Green: Normal audio levels / Red:Excessive audio levels).