You will feel comfortable by wearing this earphone because it uses not-in-ear and bone conduction design. The large-capacity battery of this earphone supports long endurance. Featured with a Bluetooth-compatible chip, this earphone can bring you quick, stable and anti-interference transmission as well as stereo sound effects and an HD-compatible calling experience. It is constructed of ABS material. The length of this product is 7.8cm, the width is 4.8cm and the height is 2cm. This wireless earphone is suitable for listening to music, doing sports, calling and so on. Item Name: Wireless Earphones Material: ABS Features: No Latency, Sensitive, Subwoofer Speaker Unit: 13mm Frequency Range: 20Hz-20KHZ Microphone Sensitivity: 94 Minus or Plus 3db Transmission Range: 10-15m Transmission Rate: 24mbps Talk Time: 6-7 Hours Listening Time: 6-7 Hours Headset Battery: 50mAh Standby Time: 150 Hours Rechargeable Compartment Battery: 350mAh, Charge Times: More Than 3-4 Times Size Details: Size: 7.8cm x 4.8cm x 2cm/3.07" x 1.89" x 0.79" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 Pair of Wireless Earphones 1 x Charging Case 1 x USB Cable 1 x User Manual