Recording Tech WM200 2ch Wireless Microphone

Frequency range: 640MH2-690MHz;
Effective working distance: 250 meters;
Audio frequency response: 40Hz ~ 1800Hz t3dB;
Dynamic range: 92 dB;
Signal-to-noise ratio: 103 dB;
Total harmonic distortion: $0.8%, @1KHz;
Working temperature range: -100 ~ +503,
Power supply mode: D 12V/500MA;
Normal working current: 12V: 500mA;
Power supply: AA 1.5V x 2;
Channel: 2*100;
Channel spacing: 250Khz;
Frequency synchronization method: manual button setting;
Frequency seting.Infrared synchronous frequency binding