VoiceBooster Voice Amplifier & Mp3 Player & FM Radio 25watts Black MR-AK38 (Aker) by TK Products,Portable, for Teachers, Coaches, Tour Guides, Presentations, Costumes, Etc. Small Super Powerful Voice Amplifier/Speaker Mp3 player & FM Radio. Size is 3.7in diameter x 5.8in length 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 7,000 square feet. USB port and MicroSD Port with controls for playing Mp3 music. Can also be used as a speaker for external Mp3 players. 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. FM Radio with automatic tuning. 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, USB and MicroSD port, MP3 controls, adjustable waist band, Carry bag.