Horrible! Made of what can only be described as cheap, substandard material, do not buy these if you plan to use them regularly.  My wife used these 1 to 2 times per week since we bought them in June 2014.  The green and blue straps broke after only 10 months of use.  After 2 months, we noticed that the rubber had begun to deteriorate on all of the bands.  I will never Black Mountain Products resistance bands again.