... ,LED display 4.property:compatibility 5.2.4GHz,USB jack Battery Operated MicrophoneFUNCTION:1.Multichannels:It has more than 1000 channels ... .5.LED display charging status,balanced battery,volume.6.Page turner,USB upgrading.7.Lithium battery.8.It can work for 33 ... hours: 33hours Standby time: 70days Working Voltage: 3.7V Alkaline battery Working Distance: ≤80 meters Working Temperature: -30-50°C Weight ...