Main Features:- Double channels design, can use two handheld wireless microphones without interference at the same time.- High precision quartz crystal to lock the frequency.- High sensitivity and high S/N ratio, high fidelity without noise.- Superior selectivity, multi-channel can use at the same time, do not interfere with each other.- Suitable for studio / karaoke / radio / etc.- Ideal environment for using distance is up to 50 meters, complex environment and practical distance is 30 - 40 meters.System Parameters:- Carrier frequency range: 220 - 270MHz- Frequency response range: 60Hz - 16KHz- Harmonic interference: more than 90dB- Radio frequency stability: plus or minus 0.005 percent- S/N ratio: more than 90dB- Output intensity: 0 - 400mv- Harmonic distortion: less than 0.5 percent- Microphone is powered by 2 x AAA battery ( not included )- Microphone dimension: 260mm x 30mm x 30mm- Receiver dimension: 110mm x 45mm x 15mm