Main Features‎:‎MARROW 303B wireless Bluetooth 4.0 music headphonesAdopts chipset‎,‎ work more smoothlyHiFi quality‎,‎ delivers a clear and delicate soundPowerful bass music effect‎,‎ excellent listening experienceErgonomic design‎,‎ feel no fatigue after a long time wearingProtein leather material‎,‎ ultra‎-soft earmuff‎,‎ super comfortable to wearBuilt‎-in 450mAh rechargeable Li‎-polymer battery‎,‎ up to 20h working timeLightweight and portable to carry out Brand‎:‎ MARROW Model‎:‎ 303B Color‎:‎ Black‎,‎Blue‎,‎White Wearing type‎:‎ Headband Function‎:‎ Answering Phone‎,‎Bluetooth‎,‎HiFi‎,‎Microphone‎,‎Song Switching Connectivity ‎:‎ Wireless Connecting interface‎:‎ Micro USB Application‎:‎ Mobile phone‎,‎Portable Media Player‎,‎Sport Driver unit‎:‎ 40mm Frequency response‎:‎ 20‎-20000Hz Impedance‎:‎ 32ohms SNR‎:‎ 80dB Sensitivity‎:‎ 106db Talk time‎:‎ 20h Music Time‎:‎ 15h Standby time‎:‎ 135h Charging Time ‎(‎h‎)‎‎:‎ 3h Bluetooth‎:‎ Yes Bluetooth version‎:‎ V4.0 Bluetooth distance‎:‎ W/O obstacles 10m Bluetooth protocol‎:‎ A2DP‎,‎AVRCP‎,‎HFP‎,‎HSP Bluetooth mode‎:‎ Hands free Battery Capacity‎(‎mAh‎)‎‎:‎ 450mAh 0.486 Package weight‎:‎ 0.53716 kg Product size ‎(‎L x W x H‎)‎‎:‎ 16.00 x 19.00 x 3.00 cm / 6.3 x 7.48 x 1.18 inches Package size ‎(‎L x W x H‎)‎‎:‎ 21.50 x 23.00 x 6.10 cm / 8.46 x 9.06 x 2.4 inches Package Contents‎:‎ 1 x Headphones‎,‎ 1 x USB Cable