Combining Sena's leading Bluetooth communications platform with an integrated 4K camera, the 10C EVO allows for easy rider communication and video recording. The 10C EVO's compact, aerodynamic design is optimized for helmets as it hugs close to the outer shell. This results in reduced wind resistance and noise, improving your audio experience.Working distance of up to 1 mile (1.6Km) in open terrain.Supports of up to 4 riders.20 hours of talk time from a rapid 2.5 hour charge.Built-in 1200 mAh Lithium Polymer battery provides long life use.Sena s premium HD speakers are redesigned and optimized for both physical comfort and unmatched audio performance. Designed with a beveled taper, the HD speakers fit easily into helmet pockets and give riders a more comfortable experience. Sena s HD speakers offer a marked increase in volume, bass boost, and clarity.The camera s integrated communication system mixes audio from the intercom and music from your smartphone into your video, on the fly. Sm