Bluetooth Stereo Headphones, Bluetooth 4.1, Noise Reduction, Line-in Function & Hands-free Supported, OEM/ODM available. > >Features: >Driver Unit: ø40mm x 2 >Impedance: 32Ω >Sensitivity: 97±3dB S.P.L at 1KHz >Response (system): 20Hz~20KHz >Rated Power: 20mW >Aggregate capability: 40mW >Power Supply: Lithium battery/DC 5V >Built-in 400mAh rechargeable battery >Plug Type: Micro USB >Bluetooth Version: V4.0 >Support: HSP, HFP, A2DP, AVRCP profiles >BT Transmission distance: 10-15m >Built-in microphone for calling function >Soft headband & ear pad to bring comfortable wearing >Unique & fashionable design >Clear & powerful sound >Support AUX IN function > >Shenzhen Aoni Electronic Industry Co., Ltd