I wanted to try resistance bands to supplement my dumbbell workout. Looked at some different brands, and purchased these because of the positive reviews. Upon opening the package, it was immediately clear that these were very high-quality. They are actually much better than I expected. Professional gym quality - definitely heavy duty. I also love the fact that you can combine the different bands to increase the weight/resistance. Great company that obviously puts pride in the products they sell. Highly recommended!