Black Mountain Products makes the best Resistance Bands around. They also have the best life time guarantee, and awesome customer service. I've been using the bands, and over time the years the bands are starting to get worn and splitting, and one email to Black Mountain and they sent me FREE of charge, FREE shipping, replacements on the blue, yellow, and green bands that I use the most. THEY ARE AWESOME FOLKS at BLACK MOUNTAIN!!! You can't go wrong, and they are always there!!!