Receive your calls easily with your Twiins D1 hands-free. Very easy to install, it fits in most helmet models, & it is fully integrated inside the helmet. Specifications: Connect your phone & receive calls using only one button. Ready to connect with cellular phones & smartphones Bluetooth®. Compact & miniaturized electronics integrated on one speaker. LED red/blue indicator showing the state of functioning integrated on the microphone. Intercom available by linking with a Twiins D3 or D2-HSAi Answer your calls or follow GPS instructions. Rechargeable by USB (Universal Serial Bus). Easy to install.