The new Cardo SMARTH communication system was designed for optimal fit with HJC helmets and it does so in a remarkably striking way. Equipped with Cardo's groundbreaking DMC technology Dual-technology: Dynamic Meshwork Communication (DMC) and Bluetooth 4.1 in a single, powerful and ultra-sleek communication system. the Cardo SMARTH offers the most robust and versatile multirider intercom-conferencing experience available today. Up to 13 hours talk time or one-week standby Fully waterproof and dustproof - IP67 certified Make, receive or reject calls by voice command or at the push of a button Dual hands-free profile allowing connectivity to two mobile phones and GPS simultaneously Up to four riders can maintain uninterrupted communications within a range of up to 3.6 km/2.25 miles between two to four riders Intercom-to-phone automatic call transfer from intercom to mobile phone when out of range Mobile conference call with outside caller and intercom partner Allows intercom conversations with non-Cardo headsets FM radio with RDS and six built-in station presets, auto scan and seek Music-sharing allows two riders to listen to the same radio station, with each being able to change the station Superb high-definition audio quality with replaceable, ultra-thin 40 mm speakers and 3.5 mm jack