Martian Motorcycle Bluetooth Helmet Modular Full Face Flip up Dual Visor Bluetooth Headset: HM-BH1 Glossy White

<b>Helmet Size Chart</b> <br> <br> S 53-54 CM 20.9/21.3 Inch <br> M 55-56 CM 21.7/22.0 Inch <br> L 57-58 CM 22.4/22.8 Inch <br> XL 59-60 CM 23.2/23.6 Inch <br> XXL 61-62 CM 23.8/24.1 Inch <br> <br> <b>Helmet Size Tips</b> <br> <br>(1)Wrap a measuring tape around your head about a half-inch above eyebrows <br>(2)Take measurement two to three times to pick the largest one.

• DOT Approved; Size M (55-56 CM,21.7/22.0 Inch); Advanced Modular/Flip up and Dual Lens Design (inner smoked lens/outer clear shield);
• Motorcycle Bluetooth Headset supports up to 3 riders intercom, 500 meter communication, 12 hr phone talk time, 9 hr intercom talk, 3 hr charging time and 120 hr standby time;
• Advanced DSP echo cancellation and noise suppression technology provides clear music and intercom talk with built-in 2 premium speakers with full stereo sound
• Compatible with most mobile phone, Ipad, GPS audio via Bluetooth 3.0 technology; Easy one touch phone call, music playing, FM radio control;