Movo WMIC50 2.4GHz Wireless Lavalier Microphone System with Integrated 164-foot Range Antenna (Includes Transmitter with Belt Clip, Receiver with Camera Shoe, Lavalier and 2 Earphones) Includes Transmitter with Belt Clip, Receiver with Camera Shoe/Tripod Mount, Lavalier & 2 Earphones 2.4GHz Wireless system features internal boost antennas with a 164-foot (50-meter) range Receiver headphone features second isolated microphone to communicate with the transmitter headphone (audio does not pass through to output) Audio input/output: 3.5mm Transmitter and receiver are each powered by two AAA batteries (not included) which provide 3.5-4 hours of runtime RF Modulation: GFSK Frequency Band: 2.4GHz (2405-2478MHz) Frequency Response: 35Hz-14KHz3dB Signal-to-Noise Ratio: 76dB or more RF output level: 5 mW Reception sensitivity: -85dB +/- 3dB / 0dB=1V/Pa, 1kHz Audio input/output: 3.5mm Operation range: 50 Meters (164 ft) Power requirements: Transmitter and receiver are each powered by two AAA batteries Battery life: 3.5 to 4 hours of runtime Transmitter Dimensions: 2.36 x 3.3 x 1.1&#034;; 4.37 oz. Receiver Dimensions: 2.36 x 3.3 x 1.61&#034;; 4.89 oz.