Fitronix nylon cloth resistance tube is suitable for fixed use at home, office and gym for full body exercise, which is a very effective training tool to enhance core strength, cardiovascular endurance and coordination. Internal tube, has high elasticity, high tensile strength, good rebound, and is not easy to deform. A strong and durable aluminium climbing buckle is for connection and fixation, which is very durable. It has four resistance values tubes (10/20/30/40LBS)