... Portable Microphone for teachers,meeting,restaurant,etc Multifunction all in one with Entertainment,Microphone, Amplifier, Loudspeaker,Music play ... : rechargeable with high capacity cylindrical L--Battery, keep working with 20 hoursWith digital display, also show bettery usageOuput ... -53±3dB Recharge Time 4-6 hours Battery working time keep working in 8-12 hourse Function Mp3, FM radio, Amplifier, ...