If you spend more days on the mountain than off, the Smith Quantum is your helmet for bomber protection season after season. In addition to a hybrid shell that adds durability, the Quantum's secret comes from using Koroyd® throughout the helmet, a fully-vented material that absorbs more energy in a crash than traditional foam construction alone. Add MIPS® for increased safety during angled impacts, and you have our most advanced helmet design. Since all this protection is useless if you don't want to wear it, we dialed up the comfort level with a system that micro-adjusts around your whole head. A sweat-wicking, odor-fighting liner keeps you warm, while an easily adjustable 22-vent design lets you adjust airflow as needed.