From TK Products, LLCModel: Aker MR-AK38Color: BlackPeak Power output: 25 WattsFrequency response: 100hz ± 13db1khz ± 1dbDimensions: 3.74in Diameter x 5.79in Length (95mm x147mm)Weight (w/ Batteries): 1.72 lbs (780 g)Voltage: 7.5vCurrent consumption: 150mA Speaker Sensitivity: 53 dBV/A +- 3 dBPower Source: Built-in Lithium Rechargeable batteriesBattery Life: 10-15 hours, 6 hour recharge, 2-3 year life (replacements available)Also included: 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.Possible Uses: Costumes, Props, Electronic sound effects, MP3 player, Teachers, Professors, Ministers, Coaches, Tour guides, and Presentations.Features: - Built in FM Radio - USB and MicroSD port for playing MP3 music and sound files - Rechargeable lithium batteries that last 10-15 hours of continuous use before needing a charge. - Battery life will last 2-3 years. - Sound covers over 6,000 square feet. - Comes with adjustable waist or neck band - 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.