Special Features : ?IPX5 Waterproof 3W speaker, Bluetooth 4.1, Impedance 4?, Driver Size 50mm, Signal to Noise Ratio 80Db, Sensitivity 1kH, Total Harmonic Distortion 1%, Maximum SPL 90dB, Playback Time Up to 10 hours, Talk time 12 hours, Standby Time up to 30 hours, Built In Mic, Bluetooth Range 10m, Caution - Don't play while charge