The MediCordz Modular Bungie Kit stabilizes the back with rowing and back muscle exercises to improve strength and flexibility. The MediCordz Modular Bungie Kit comes with 2 modular handles, two, 3-ft (90 cm) modular Bungie Cordz and 2 combination mounts. Interchangeable. Available in seven levels of resistance. Silver resistance has 1 - 7 lbs of pull.