Features: C This KOTION EACH B3505 wireless Bluetooth Stereo headphone with remarkable sound, it is a good choice for listening music, watching movie, chatting online, etc. C Wireless Bluetooth headset, compatible with Bluetooth enabled devices, such as for iPhone, iPad, HTC, Lenovo, Samsung, Tablet PC, etc. Bluetooth Version: V4.1+EDR Operation Distance: 10m Speaker Diameter: 50mm Microphone Unit: 4 x 1.5mm Impedance: 32ohm S.P.L: 106dB S.P.L. at 1KHz Frequency Response: 20HZ-20,000HZ Battery: Built-in rechargeable 3.7V/250mAh lithium-ion battery Music Time: Approx. 10 hours Talk Time: Approx. 11 hours Standby Time: 250 hours Input DC: 5V/130mA Charging Time: Approx. 3 hours Plug Type: 3.5mm stereo