Windproof and waterproof design ensures a stable connection. Equipped with noise reduction technology, high volume output, and extended battery life. This helmet headset delivers clear, high-quality stereo sound and is compatible with all smartphones. Deep bass and crisp treble response effectively solve the issue of low o volume during riding. A wireless helmet headset that automatically connects, providing strong signal transmission for efficient and convenient cycling communication. Powerful signal performance ensures smooth and uninterrupted communication. The detachable nylon design allows for easy installation into the helmet, with secure and firm fixation. Bluetooth range: 10M Answering: Automatic Input: Bluetooth Speaker diameter: 50MM Charging voltage: USB 5V Frequency response: 80Hz - 20kHz Distortion: Less than 1% Signal-to-noise ratio: 80dB Power supply: Built-in lithium battery 800mAh Size: 6cm Material: ABS Color: Black Package Contents: 2 x Headphones 1 x Charging Cable Note: Light and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3cm.