Uses UHF technology, wireless remote transmission makes use easier without annoying cables, can achieve 20m transmission distance. Wider frequency range, less interference, shows your voice and perfect. Adopts the precise complete electronic circuit control, captures rich sound from sources directly in front of the microphone. For all events such as karaoke, live performances, conferences, schools, halls, parties, etc. USB receiver power supply via USB charger, power bank and more. Suitable for studio/karaoke/radio/etc. V20: frequency: A:262.85MHz B:268.85MHz distance: 30-50s PCB board: +5-9V Audio frequency response: 40HZ~15KHZ Audio dynamic range: more than 100dB Audio output: 0-200mv Maximum operating distance: more than 80 meters/m Receiver supply voltage: 3.7v-4.2v (lithium battery) Receiver working current: less than 80mA Receiver continuous working time: standard (3.7v/800mA) 10 hours Transmitter working current: less than 80mA Transmitter working time: 10-18 hours Color: black Material: plastic Size: 250x50mm Package contents: 1 x pair of microphones 1 x adapter 1 x connection cable 1 x receiver (without battery) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.