It strengthens everything from the shoulders to the arms to the legs. And you can carry all of this out in the comfort of your home. Ideal for both men and women, there aren't many portable devices like this rubber chest expander that can offer such a wide range of benefits. The high tensile strength and elasticity ensures that you'll be using this expander for many workouts post-purchase. The resistance tubings in the expander are made of the best quality rubber latex. Take it with you anywhere, as it's light and easy to carry.