X-Core Resistance Bands - SetThe Pack comes with six sets of X Core Cords in 3lb, 7lb, 10lb, 15lb, 25lb, and 40lb resistance levels. These cover the needs of most athletes, but if your facility caters to beginners or high level competitors, adding extra resistance options is a smart move. Most squat racks and pull up rigs have uprights spaced between 1. 1m and 1. 8mperfect for setting up a X Core station. Designed to improve shoulder function and performance, the X Core System