I also buy these for use with the ChaLean Extreme program , by Beachbody , which require a lot of weight change througout the workout . they work sufficiently for lifting and for basic exercise . the quick change option be really nice and there be a diverse amount of weight . I would not call this the highest quality product though . they seem flimsy for be close to $ 200 . I be always a little afraid that the pin be go to slip out and cause a injury .