FlexMetal ½ lb patented weight vest inserts provide a superior fit compared to vests that use steel shot, sand, or steel bars. They are flexible, small, and flat with round edges, so there are no sharp corners that dig into the athlete's body. Compatible with Univest Weighted Body Vests. Short Vest accommodates 20 lb. Long Vest includes 40 lb. Weights are available in a 5 lb Set 0f 10; weight vests not included.