Lvtube Waterproof and Dustproof Stereo Bluetooth Speaker Built-in 2x4w Speaker X-bass Waterproof Grade can reach IPX4 Bluetooth version: CSR4.0  Product Size: 180*68*71mm  Material: ABS Transmission distance:10 meters - Working time: 8hs. Support handsfree function  Frequency range:180Hz- 20KHz Battery: Built-in lithium battery, 3.7V/3000mAh