Aluminum; Portable cube-shaped wireless speaker with 2 operating modes: wireless and AUX/wired (refer to instructions) and works with most wireless-enabled devices including smartphones and tablets; Power/Technology: Rechargeable Lithium Ion Battery – 37V, Capacity: 400 mAh; Input: DC 5V; Output Power: 3W; Aux in: 35mm audio jack; Frequency Response: 50-20KHz; Speaker Impedance: 4 Ohm (?); Wireless V21+EDR; Transmission range: 10M (32 feet); Features multiple functions buttons on base of device including play, pause, stop and volume; Approx 3-5 hours of playback time; Must be charged prior to first use Charge time varies by device and environment (2 hours minimum required); LED indicator light (on bottom) shines red when charging; Speak hands-free into built-in microphone; Includes instructions, wrist strap, USB to Micro USB charging cable, and 35mm to USB line-in cable; Product Size: 1.875 w x 2.125 h x 1.875 d; 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.