Small Super Powerful Voice AmplifierUsed by Teachers, Coaches, Tour Guides, Presentations, US Army - Frequency Response: 100hz ± 13db1khz ± 1db - Rechargeable 7.4 Volt Lithium Battery * Built In Rechargeable Lithium Batteries That Last Up To 12 Hours Of Continuous Use Before Needing A Charge - Current Consumption: 150ma - Color White * Projection Range Up To 1/2 Mile - Charging Time:6 Hours - Speaker Dimensions 3.86 x 3.62 x 1.85 Inches * Includes Headset Microphone - Speaker Sensitivity: 53 Dbv/A +- 3 Db - Weight: 0.88Lbs * AUX Input For MP3 Player Or Ipod - Unit Includes Charger Belt Clip, Adjustable Waist Band Strap, Carry Bag