IMPACT RESISTANCE: The skateboard helmet adopts durable tough shell with a soft liner which could absorb external pressure caused by the crash in skating activities. Wearing the Yellow Jacket helmet will feel much safer and more confident and thus perform better in sports activities. VENTILATION DESIGN: Our helmets are designed with multiple vents special aerodynamic de-sign and breathable foam. It will reduce sweating and keeps you cool even during intense body movement. The foam is breathable and stable for use in a variety of different activities. Manufacturered by Yellow Jacket. A PERFECT FIT WITH ADJUSTABLE STRAPS: Yellow Jacket skateboard helmet comes with adjustable straps that allow the user to adjust for a better fit. The lightweight design and durable ma-terials are excellent for a number of different activities. Sizes: Small 19.5 - 22" Medium 21.25 - 23.5" Large 22 - 24.5" 100% MONEY-BACK GUARANTEE: Dont worry about money we are so convinced in our hel-mets that if they don't live up to your expectations you can send them back for a full complete re-fund so you have nothing to lose! DUAL SAFETY STANDARD: Our dual safety standard certified bike and skateboard helmet meets ASTM F-1492-08 and CPSC-1203 safety standards for skateboarding and tricks roller skating.