DS18 DS-MICUHF22 DUAL 2 Channel UHF Microphone With Display Dual 2 channel UHF microphone with Display Audio Frequency Response of 40 Hz - 20 KHz, Dynamic Range of 80dB, and a system Distortion of 0.5 Percent This system Carries a Signal-to-Noise Ratio of 95dB and an Operating Range of 300 Feet Operation Temperature: 41-104 Degrees Fahrenheit Carrier Frequency Range: 629 - 661 MHz Batteries Included