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 and ventilation without excess bulk. And the fit is luxurious and secure, thanks to our highly-adjustable Roc Loc 5 Air MIPS® system that allows you to customize fit/feel for great stability and long-range comfort. Another benefit is integrated MIPS® which can provide an added measure of protection from rotational forces in the event of an angled impact.