Surmount Primaloft Vest M is made for the active alpine ski tourer. This is lighter than the jacket in the same range, giving you even more movement. The already revolutionary PrimaLoft® insulation is now even more impressive with the new Air Gel Cross Core technology; which allows the garment to be thin yet an impressive thermal insulation effect. For full weather protection, use Surmount waterproof insulation on the outside of a Surmount PrimaLoft® product.