Audiodesign Fixed frequency VHF wireless microphone set, mute function on the microphone

Specifications:
-Mute function on the microphone
-Polar pattern: Supercardioid
-Microphone capsule with neodymium magnet
-1/2" microphone capsule coil
-1" microphone capsule membrane
-Available frequencies: 174.50 - 175.50 - 176.40 - 183.57 - 185.15 - 191.30 - 197.15 - 203.40 - 209.15 - 215.20 MHz
-Powered by two AA batteries
-Battery charge indicator on the microphone
-Output volume separately adjustable
-Output with summed channels Jack
-Receiver size: 1/2 module
-Frequency response: 40Hz - 16Khz (+/- 3dB)
-Oscillator type: quartz
-Frequency stability: 10 PPM
-Radio frequency stability: +/- 0.005%
-Receiver sensitivity: -100 dBm
-Signal to Noise Ratio (SNR): > - 90 dB
-Transmission power: 0- 400 mWatt
-Total harmonic distortion: < 0.5%
-Operating temperature: - 20 / + 50 °C
-Working distance: up to 100m (in open field).
-Code: PAMV10
-NB The distance depends on the absorption and reflection of the radio frequency by the surrounding environment as well as on local interference due to other transmissions (e.g. radio links, TVs, cell phones etc. etc.)