These latex-free resistive bands are good for those of us allergic to latex. But I didn't know which level of stretchiness would be right for me, so I started with level 1. The bands were tough and stood up well to use, even when closed into a door hinge for leg exercises. But in a couple of weeks I realized that level 1 was too easy to stretch and did not give me enough resistance, so I ordered level 3, which suits me very well.