n music and phone calling mode freely. ?7. Bettery shown on Iphone. Automatically connect to the last connected Bluetooth device. 8. With FCC, CE, ROHS approval. Function characteristics:Bluetooth Version:CSR4.0Bluetooth Headphone(1) With bluetooth function(2) With Microphone function ????????????????? ? ? ? Output power:0.25W*2Frequency:20-20,000HzTransfer Distance:33ft (10m)Impedance:32 OHM(Ω)Lithium battery capacity:250mAhPlay/Talk time;5-6hoursCase Material:ABSDimension