Aluminum case cylinder wireless speaker with steel mesh cover and no-slip bottom PowerTechnology Rechargeable Lithium Polymer battery 3.7V, Capacity 350 mAh Input DC 5V OutputPower 3W Aux in 3.5mm audio jack Rated Impedance 4 Ohm Speaker 1.6 inches Frequency response 90-20KHz SNR 85d Sensitivity 80db 2db Distortion 0.3 Transmission range 10M (30 feet)Wireless V4.0. Playback time 2-4 hours. Connects to your mobile device using wireless technology or through the 3.5mm audio cable (not provided) Push button to answer phone calls. Speak hands-free into built-in microphone Also play MP3 files though a USB flash drive or TF card Instructions and charging cable included. CE and FCC approved.