... , church, parade, lecture, auction, sales promotion, tour guide etc. Features:- With lithium battery and Ni-MH battery adjustable design- Compact and ... Microphone- Adjustable WaistbandFunction:1. Multifunctional digital amplifier all in one with microphone, AV amplifier and loudspeaker2. Adopt high-tech digital circuit ... wont notify you in advance! Thank you 15W Mini Speaker with long stand-by time