DESC: Designed for men, this replacement hipbelt fits the REI Mars backpacks. Medium fits waist sizes 28 - 48 inches and large fits 33 - 60 inches. Pre-curved waistbelt with a Delrin hoop is designed to cradle hip bones for a more natural fit and distribution of pack weight without sagging. V-pull waistbelt allows you to use a natural forward pulling motion for quick, easy cinching and precise adjustment.