The SE5 Composite features an aerospace fiberglass composite shell, lightweight stainless-steel d-rings, dual-density EPS, in-molded MIPS brain protection system, EPP chin bar liner with collarbone suspension system, quick release XT2 3D cheek pads, a Dri-Lex comfort liner, and smart shear plastic visor screws for easy impact break-away.Shell Material – FiberglassShell Sizes – 3Rotational Device – MIPS IntegraImpact Liner - 3 PC Dual Density, Blue/Black EpsComfort Liner – Dri-LexCheekpads – Quick Release 3DInner Chinbar – EPPD-Rings – Stainless SteelVisor Screws – Breakaway PlasticCertifications – DOT/ECE, ECE (EU)MIPSMIPS (Multi-Directional Impact Protection System) is a specialized helmet safety technology that is now being used in the top tier of off road helmets in order to greatly lessen the chances of traumatic brain injury.By integrating an engineered low-friction layer into the liner of the helmet, MIPS enables a relative sliding motion between the head and the helmet so angular and rotational impact forces are absorbed and deflected.Since most head impacts occur at oblique and unpredictable angles, helmets with MIPS Technology are able to offer better protection than helmets without.For proper fit and size, measure the circumference of your head 1" above your eyebrows around the largest portion of the back of your head.Sizing Information:21 5/8" - 22" ........... Small22 3/8" - 22 7/8" ....... Medium22 7/8" - 23 1/4"........ Large23 5/8" - 24"............ X-Large24 3/8" - 24 7/8"........ XX-Large