The S1 Lifer Helmet is one of the best fitting and safest helmets for Skateboarding, Longboarding, BMX, Scootering, Roller Skating and Roller Derby. The Lifer Helmet uses a specially formulated EPS Fusion Foam which allows it to protect your head from multiple low force impacts as well as high impacts. The Lifer Helmet is a certified "multi-impact" helmet and is up to 5x more protective than the soft foam non-certified helmets. The Lifer helmet is a break through design combining the added safety of a CPSC and ASTM certified helmet with the comfort and fit of a non-certified helmet. The S1 Lifer Helmet is the best fitting High impact and Multiple Impact helmet on the market. Please be advised that extra sizing liners are not included. Comes in size specified. Please use sizing chart to determine your size.