Product details:
DOT Approved; Size S (53-54 CM,20.9/21.3 Inch); Helmet comes with spoiler and motorcycle bluetooth headset as bundle (installation required); Advanced Modular/Flip up and Dual Lens Design (inner smoked lens/outer clear shield); Motorcycle Bluetooth Headset supports up to 3 riders intercom, 800 meter communication, 10 hr phone talk time, 7 hr intercom talk and 300 hr standby time; Compatible with most mobile phone, Ipad, GPS audio via Bluetooth 3.0 technology; Easy one touch phone call, music playing, FM radio control; Aerodyname Spoiler mounting helps helmet steady and stylish looking; 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 23.2/23.4 Inch br XXL 61-62 CM 23.8/24.1 Inch br br 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.
