The Fitness-Mad Power Resistance Loop – Extra Strong – brings you a flexible way to strengthen those muscles and train that core. This handy training tool can be used on its own or can be paired with fitness apparatus or equipment for a wide range of exercises to strengthen muscles and for core conditioning. It features heavy-duty latex construction for excellent durability and reliability. It is also suitable for rehabilitation. Use anywhere – portable and lightweight, you can sling it in your gym bag or over your shoulder with ease. Extra Strong Resistance Loop.