THE SYNTAX COMBINES A TOUCH OF EUROPEAN FLAIR WITH SLIGHTLY DEEPER COVERAGE & HIGH-PERFORMANCE FEATURES—ALL TUCKED INTO A VERY SLIM DESIGN. The outer shell is molded from a tough polycarbonate thats fused permanently to the EPS foam liner using our In-Mold construction process to enhance durability & ventilation without excess bulk. & the fit is luxurious & secure thanks to our highly-adjustable Roc Loc 5 Air system that means that you can customize fit/feel for great stability & long-range comfort. SPECS- Ionic+™ anti-microbial padding- Featherweight webbing with- Slimline™ Buckle CONSTRUCTION- Full-wrap In-Mold polycarbonate shell with EPS liner- Four polycarbonate hardbodies FIT SYSTEM- Roc Loc 5 Air Mips VENTILATION- 25 Wind Tunnel™ vents with internal channeling SUPER FIT™ SIZES- S 20”–21.75” / 51–55cm- M 21.75”–23.25” / 55–59cm- L 23.25”–24.75” / 59–63cm- XL 24”–25.55” / 61–65cm CERTIFICATION- Complies with the US CPSC Safety Standard for Bicycle Helmet for Persons Age 5 & Older