Bluetooth version: V4.2 Battery capacity(erabuds): 55mAh Battery capacity(Box):500mAh(Provides 3-4 Times Charges) Adopt the advanced CVC6.0 active noise-cancellation Charging time: 1 hours Work time: one for 3-4 hours, and a set for 2-3 hours Stand-by time: one for 120 hours, and a set for 60 hours Wireless range: a set for above 10m