The Sena Technologies Rider Link (SRL) is a sleek and low profile communication system tailored specifically to the Shoei NEOTEC II helmet. Discreetly placed within the helmet instead of being attached to the side like other devices. The SRL operates with a simple 3 button functionality, to allow easy navigation through the commands and settings. If that's not enough Sena Technologies has a smart app that can be downloaded to you phone for an even easier way to adjust your device. Pairs up to 8 Riders Up to 1 Mile/1.6 Kilometer Range (With Clear Sight) 10hr Talk Time Noise Cancellation: Advanced Noise Control GPS Navigation (When Paired with GPS from ether your bike or Phone) Built in FM radio Battery charging time: 2.5 hours Bluetooth 4.1