MAX MOTORSPORTS..Family-owned and operated in the USA Thank you for supporting small business! O'Neal Adult Pike IPK Bicycle Helmet Lightweight enduro / trail / freeride helmet with a 2 shell polycarbonate construction. Features: Compact, two-part racing shell with high quality workmanship Weight: 390g (± 25g) Integrated IPX ACells helmet rotation impact absorption technology for maximum protection Easily adjustable helmet peak with ratchet mechanism Goggle compatible at the highest setting Unique `dual-flow` system with enlarged air slots for maximum air circulation 3D size adjustment for a perfect fit Fidlock magnetic closure for easy, one-handed opening and closing Sweat-absorbing, washable and replaceable inner lining Exceeds the EN1078 safety standard for bicycle helmets With tape level, measure the widest point of your head, approximately 1/2 to 1 inch above your eyebrows. Helmet Size CM Inches S/M 55 - 58 20 1/2 - 22 3/4 L/XL 59 - 61 23 1/4 - 24 Domestic Shipping Free USPS or UPS shipping included - USA customers only