HeroNeo&reg; Soft Warm Beanie Hat Wireless Bluetooth Smart Cap Headphone Headset Speaker Mic (Dark Gray) Knitted material, fashion and keep warm with answer the phone in winter Set-in Li-ion chargeable battery, charge via USB Cable, long stand-by time. Transmission distance: 30ft or so , Transmission distance of MIC: 3 ft Bluetooth Version: V3.0+EDR Frequency: 2.4026GHz-2.480GHz