The upgraded Bluetooth 5.1 chip has wider wireless coverage and more stable transmission signals. High-precision and high-performance silicon microphone, you can listen at ease without fear of interference. 3.5mm stereo connector, plug and play, lossless sound quality, support power-off memory. Widely compatible with plug and play Audio equipment with AUX input interface can be used. rid of the shackles of cables and listen to /voices more freely. Bluetooth version: 5.1+ Battery capacity: 280mAH Playing time: about 12 hours Working current: 15~20mA Ear wire length: 200mm Product size: 11.5x20.5mm Colour:black Material:ABS Package Contents: 1 x Adapter 1 x Metal Plug 1 x Audio Cable 1 x USB Cable 1 x English Manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.