The Smith Women's Mirage MIPS Snow Helmet combines single-zone adjustable venting with lightweight in-mold construction for a helmet experience that is reduced down to just what you need for a day on the hill. The dial-fit system and cozy long-fleece liner ensure that you are comfortable and warm. The Mirage exemplifies Smith's belief that every detail should be considered. MIPS is used to reduce the rotational forces to the brain in the case of an oblique impact. Smith helmets are created to absorb direct impacts very efficiently and when combined with MIPS, Smith helmets absorb oblique forces better by allowing a small rotation of the outer shell relative to the liner.