Windproof and waterproof connection is more stable. DSP noise reduction technology, high volume and high battery life. This helmet headset transmits clear and high-quality stereo music, compatible with all smartphones Deep bass and crisp treble response can perfectly solve the problem of not being to hear the earphone sound when riding. A helmet wireless headset, automatically connected to enjoy music, the connection signal is strong. Provide efficient and convenient cycling communication. Powerful signal transmission allows you a smooth and unimpeded communication experience. The detachable Nylon is easy to install in the helmet, and the fixation is firm Bluetooth distance: 10M Answering : automatic Input : Bluetooth Speaker specifications: diameter 50MM Charging voltage: USB5V Response frequency: 1 80-2000KHZ Distortion: Less than 1% Sound to noise ratio: 80dB Power supply mode: built-in lithium battery 800MA size:6cm Material:ABS colour:black Package Contents: 2 * headphone 1 * charging cable Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.