Electro-Voice R300-L-A Uni-Directional Lapel Wireless Microphone System Designed for club sound, performance & sports venues and other applications ClearScan - find the clearest channel available with the touch of one button EZsync - infrared channel transfer from receiver to transmitter for easy and error-free setup 14 hour battery life from two AA alkaline batteries Rugged metal transmitter with backlit LCD display and battery gauge