Feature: Microphone wireless system feature XLR interfaces, just plug on and turn your favorite mics into wireless mics.  Adopting advanced wireless UHF technology, the signal transmission becomes more stable.  Equipped with 10 groups of channels, you can switch the channel as your requirement, so as to avoid interference from other equipments.  Built-in rechargeable lithium battery, support continuous working up to 3 hours, after being fully charged.  Widely applicable for live streaming, recording studios, meeting, speaking, interviewing, karaoke, etc. Get rid of wire limitations, allowing you to enjoy the fun and convenience of wireless.   Specification: Model: UR-4;   -- Transmitter --;  Microphone Max Input: 1.5VRMs;  RF Carrier Frequency Range: 901m-910m;  Max Transmitting Power: 8dbm;  Working Temperature: -20℃-80℃;  Working Current: 120mA;  Battery Capacity: 700mAh;  Transmitter Size: 9.2 * 3.1 * 2.1cm / 3.6 * 1.2 * 0.8inch;  Transmitter Weight: 67g / 2.4oz;   -- Receiver --;  Max RF Input Signal Amplitude: 10dBm;  Receiving Carrier Frequency Range:90m-910m;  Receiving Sensitivity: -85dBm;  Audio SNR: 96dB;  Working Temperature: -20℃-80℃;  Working Current: 120mA;  Battery Capacity: 1500mAh;  Receiver Size: 9.9 * 3.1 * 2.1cm / 3.9 * 1.2 * 0.8inch;  Receiver Weight: 82g / 2.9oz;   Package Size: 15.8 * 15.8 * 3.5cm / 6.2 * 6.2 * 1.4inch;  Package Weight: 360g / 12.7oz;   Packing List: 1 * Transmitter;  1 * Receiver;  2 * USB Cables;  1 * User Manual;   Note: By default, the first channel is set as the preferred pairing channel everytime starting up.