There are mountain bikers and there are mountain bikers. The vast majority are content to stay within the limitations of their own abilities and the capabilities of their equipment. The hardcore, however, are constantly pushing to find the very limit, and, at times, crossing it. For those riders, POC has developed the Cortex DH MIPS Helmet. The Cortex DH is POC's crown jewel helmet, incorporating the best of the manufacturer's technology. It starts with Double Shell Anti Penetration technology. The outer shell is tough, lightweight carbon fiber. This is backed by an Aramid ballistic penetration barrier. This is made with the same stuff that makes bulletproof vests bulletproof. Finally, a thin polycarbonate shell covers the EPP liner material. The result is a lightweight, low profile helmet that stands up to just about any impact. POC uses this dual shell technology to improve its ventilation system as well, by off setting the vents to work efficiently without compromising protection or creating weak spots.POC also employed MIPS technology in the the Cortex DH. Because most impacts occur at an angle, rather than straight on, rotational energy can cause damage to the brain. MIPS offsets this danger by imitating the protection that's built into our own skulls to absorb this impact and reduce the rotational energy.