Power systems add resistance to standard strength building exercises, like chest presses and squats. Offset body weight for pull-ups and tricep dips. Bands are also a great tool for increasing flexibility and range of motion. Available in seven resistance levels: extra light, light, medium, heavy, extra heavy, ultra heavy, and super heavy. Each closed loop band is 41 inches long and is made from seamless latex rubber designed to resist breakage. Width and weight of band depends on the resistance. features: cost-effective and space-saving all-body exercise tool sturdy, seamless latex great for partner workouts light, red: 1/2w provides 5-25 lbs. Of resistance