Product features of our portable teaching wireless voice loudspeakers: 1: streamline modelling, easy to carry. 2: DC plug functions. 3: can use mobile, desktop. 4: type of machine design. Replace batteries from After charging, 5:2-3 hours for use. 6: transmitter to save electricity design, extend battery life. 1 day 9V battery power. 7: radio transmitter can control the volume of the receiving host. Suitable for various size of space to adjust, mobility. 8: advanced audio processing circuit, can be connected directly tape player, mp3, mp4 players or other audio mixed input and output amplification, reverb 35W for the sound power is more pure. Power consumption: about 30Ma Technical parameters Power supply:AH AC220V DC12V built-in 12V 1.2 battery external dc 12V manostat 2A Output power50 W(peak power)Frequency rangeVHF180 270MHzThe transmitter power30mW(max)Operation Range35MSpeaker6 inches full range horn Appearance125*240*225mmweight2.4 kgStandard Configurationthe host,Collar microphones, headmicrophones Optional accessorieshandheld wireless microphones, wireless meeting microphones, wired microphones