I be one of the people who heavily rely on review but I never write they , I do not know why but I have never write review in the past . after use these dumbbell I have to make a exception . these dumbbell be great especially in a small space , I live in a apartment and I do not have room for a whole rack of weight so I find these on amazon . I recieve they in about a week and I instantly start use they with p90x . you can switch the weight quickly which be a huge benefit when you be do any type of workout that be on a dvd or tape . they look a little awkward and they build be obviously different than a standard dumbbell but I have not have any problem with the different move on p90x . if I have to pick something I do not like , I would have to say that I do not like how much noise they make . let I explain that , the dumbbell be very solid but when you be do something like shoulder press , for example , I get a little nervous put these thing over my head because the plate `` clang '' together . it be something you get use to though , oh and one more thing when you put the pen inside the powerblock to choose a weight make sure the next plate in line do not stick to the weight you select . I pick 35 lb for one workout and the 40 lb . plate be stick to the bottom and I do not know it until the plate hit the floor , luckily I still have all my toe . well again these weight be great and I highly , highly , highly recommend these weight for someone that have a small space to put they and for someone that be do p90x .