About this item DOT FMVSS-218 Certified GDM DK-140 Full Face Motorcycle Helmet with Removable Shield (Includes 2 Shields) Aerodynamic shell design constructed using an advanced lightweight composite poly-alloy, removable and washable Liner and cheek Pads Flush-fit, side-coverless face shield that is optically correct, compound-curved, scratch resistant and protects against UV-rays 5 points of ventilation with chin, rear & forehead vents with Double D-Ring chin strap with holder for Motorcycles, Sport Bikes, ATV, UTV, Dirt Bike, Scooter, Snowmobile, and Personal Watercraft and more Please Refer to The Following Size Guide to Determine Your Correct Size. To Choose Your Correct Helmet Size, Please Measure the Circumference of Your Head 1" Above Your Eyebrows Around Your Head and Refer to The GDM Helmets Size Guide. Please Note That the Size Guide Is for Reference Only and Cannot Guarantee Perfect Fit. S: 21 5/8 – 22 IN | M: 22 ½ -- 22 7/8 IN | L: 23 1/4 -- 23 5/8 IN | XL: 24 -- 24 3/8 IN | 2XL: 24 3/4 -- 25 ¼ IN