VoiceBooster Voice Amplifier 20watts Black MR2300 (Aker) by TK Products, Portable, for Teachers, Coaches, Tour Guides, Presentations, Costumes, Etc. Small Super Powerful Voice Amplifier/Speaker. Size is 5.31in x 3.74in x1.81in (135mm x 95mm x 46mm) The VoiceBooster brand is owned by TK Products, LLC. Each VoiceBooster product comes with a 6 month parts and Labor Warranty that is serviced by TK Products, LLC. The VoiceBooster must be purchased through TK Products or one it's authorized dealers for Warranty Claims to be honored. Rechargeable lithium batteries that last 10-15 hours of continuous use before needing a charge. Battery life will last 2-3 years. Very loud, excellent clarity, low feedback. Sound covers over 6,500 square feet. Can also be used MP3 speaker. The amp has a microphone input and a MP3 input . The amp will accept signals from both input ports and out through the speaker at the same time. Comes with TK Products User Manual, Headset microphone, Charger cable (US plug), MP3 cable (male to male 3.5mm), MP3 line in port, Microphone line in port, adjustable waist band, Carry bag.