I purchased the Black Mountain Resistance Band Set based on the positive reviews I've read here on the product and the customer service. Fortunately I have not had to use the customer service. But the product is as advertised. I wanted to hold off on writing the review until I got to use the bands for a little while. I have been using it for my P90X workouts along with dumbbells and it has performed flawlessly. The quality of the bands are excellent and when you think about the cost it is a real bargain. Rarely does a product exceed my expectations but this one has. I highly recommend these bands.