Product description Color: blackwhitered Bluetooth: 4.2 Transmission frequency : 2.4GHz (2.402-2.480GHz) Transmission distance: 10M Speaker sensitivity: 1205dB Frequency response : 20-20kHz Play time: about 6-8h Charging time : about 1.5h Package content: 1*wireless mini earphone 1.NON EAR PLUG DESIGN - Upgraded headphone version is the Ear-hook design, not in-ear, free from eardrum damage. Easy to carry, suit for all peoples, do not fall when running. Wear in left or right ears, with glasses is ok. With Built-in microphone is for Hands-free calling. 2.SPEAKER UNIT IS EXTERNAL - Loudspeaker close to the ear but it is not inside the ear, will not plug block the ear canal. Listening to the surrounding environment during a call or music, Safer on the road or in some scenes and more portable for business, work. 3.Suitable for 2 ears - Suitable for the left and right ears, The ergonomic structure is adopted, and the smooth body curve is tightly attached to the ears, so that the ears are evenly stressed, giving you a better wearing experience. 4.LIGHTWEIGHT DESIGN - 10g weight, very light, no pressure or pain feeling in long time use. Ear hook designing and ergonomic design, wireless headphone affixed to the ear, suit for all peoples, do not fall when running or driving. 5.Skin-friendly material design- The surface of the body is painted with metal, it is as delicate and smooth as the skin, and it is extremely comfortable to wear every time.Built-in 90mAh lithium battery to meet your needs for large power and longer battery life.