TheraBand Professional Non-Latex Resistance Band - helps users rehabilitate injuries improve functional living enhance athletic performance and makes measuring progress and achieving goals for fitness or therapy easy. The resistance bands are easy-to-use convenient portable and are an effective alternative to free weights and weight machines. They can be used in the clinic at-home or on-the-go. They are available in 8 color-coded levels of progressive resistance giving at-a-glance documentation of progress from one level to the next and allows the user to progress as they get stronger. This is also an ideal choice for latex-sensitive users as it s not made from natural rubber latex. Color - Resistance Level / Force Blue - X-Heavy / 5.8-8.5 lbs Black - Special Heavy / 7.3-10.2 lbs