Made of Aluminum; Cylinder wireless speaker with steel mesh cover and no-slip bottom; Power/Technology: Rechargeable Lithium Polymer battery: 37V, Capacity: 350 mAh; Input: DC 5V; Output/Power: 3W; Aux in: 35mm audio jack; Rated Impedance: 4 Ohm; Speaker: 16 inches; Frequency response: 90-20KHz; SNR: = 85d; Sensitivity: 80db ± 2db; Distortion: = 03%; Transmission range: 10M (30 feet);Wireless V40; Playback time: 2-4 hours; Connects to your mobile device using wireless technology or through the 35mm 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; Product Size: 2.375 w x 2.25 h x 2.375 d x 2.375 dia.; Shipping available to contiguous U.S. addresses and Canada via Ground only.  Cannot ship via Air, Internationally or to Alaska, Hawaii, Puerto Rico and any other small U.S. island territory.