I be a p90x graduate and I have to say that the most frustrating part of the experience -lrb- unrelated to the program , of course -rrb- be use my dumbbell which require unscrew the end and slide new weight on . I be on a second program incorporate p90x , p90x + , and the One-on-Ones , and I have get much stronger since I begin p90x ; thus , I need more weight and the variation I have could not provide that . I receive these powerblock as a college graduation gift from my parent and I be happy to say that I no longer have to worry about take minute to switch out weight or about have enough weight to build more mass and strength . the weight require no assembly and be color-code to help you switch weight fast , especially if you realize that you over or underestimate you strength . while initially the pb may seem awkward to use , you adjust fast and realize that the multiple handle make for great variation in exercise . every now and then , the magnetic clip which alter the weight can get stick on different weight level , but that be rare and never a safety issue for I . whether you be engage in the p90x program or simply want a great-looking , organized weight system , the PowerBlock classic will satisfy you and last for the long haul . bring it !