Adjustable in 1/2 lb. increments! The Uni-Vest slips over the head and secures across the body with Velcro straps. Flex-Metal weights (1/2 lb. each) are evenly distributed throughout the vest and conform to the body providing exceptional balance. Weights remove easily to customize overall weight to meet specific training needs. Fits up to 80 chest. Short Vest comes with 9 lbs. of weight. Each vest alone weighs 1 lb. Weight of vests can be doubled using additional Flex-Metal weights (sold separately).