Waterproof wireless headset microphone set Waterproof wireless 2.4 GHZ headset with separate transmitter,couple automatically easy to operate , up to 4 identical systems can work together ,both transmitter and receiver work on rechargeable lithium battery worl together with battery-powered speakers for versatile solution. Removable Transmitter suitable for many different situatuins such as presentations and sports events. SPECIFICATION Frequency range: 2.4 GHZ Frequency response: 20 Hz - 20 KHz (+- 3 dB) Output impedance: 2200 ohms Pairing method: Automatic Microphone type: Condenser Microphone directivity: Omnidirectional Microphone diameter: 6 x 2.7 mm (0.2 x 0.1") Microphone sensitivity: - 42 dB (+- 2dB) Signal to noise ration: > 63 dB Power supply: Rechargeable lithium battery Power consumption: < 70 mA at 0 dBm Operating voltage: 2.0 - 10 V DC Operational distance: 25 metres (82 feet) Operational time: Up to 6 hours Included: 6.35 mm (1/4") audio adapter plug and double charger cord الحالة جديد