Special Features : ?IPX5 Waterproof 3W speaker, Total Harmonic Distortion 1%, Built In Mic, Caution - Don't play while charge, Signal to Noise Ratio 80Db, Driver Size 50mm, Bluetooth 4.1, Impedance 4?, Bluetooth Range 10m, Sensitivity 1kH, Standby Time up to 360hours, Maximum SPL 90dB, Playback Time Up to 10 hours, Talk time 12 hours