PRO DUAL WIRELESS MICROPHONES:Built-in high sensitivity professional Dynamic Bidirectional microphone core,adopts metal aluminum tube, and the net head is made of metal baking varnish, which is safe and fall-proof.Transmission distance indoor range >50ft(Outdoor range >100ft);Enhance Signal stability,No delay,No radiation,Anti-howling, Anti-jamming,Constant frequency. BATTERY AND DISPLAY:No need to set! No need to buy batteries!The chargeable receiver is built-in 1200mAh battery for 12 hours use time when fully charged. The microphone come with 2 AA 2350mAh alkaline batteries. The display can show the battery power and signal strength in real time, don't worry about Suddenly not working. ADVANCED TECHNOLOGY:Microphone and receiver use 2.4GHz connection technology, enable the microphones stronger anti-interference ability compared with UHF frequency band.Range indoors > 50ft (outdoors > 100ft); frequency response 50Hz-18kHz; signal-to-noise ratio >70dB; distortion