Resistance bands are made of eco-friendly natural latex, which is high elastic and extra durable. Comfortable Handles: The handles of resistance bands are made of PP and NBR foam materials, which are anti-slip and sweat absorption. You will feel comfortable to grip.Big Carabiner: The solid metal connecting rings are not only big-sized and sturdy but also easy to install and unload.Strong Door Anchor: The door anchor is covered by TPR buffer foam, which makes it safer and more durable.Soft Ankle Strop: The Ankle Strop is made of pearl cotton,which can reduce skin friction and therefore make you feel comfortable. 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 ensure 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.