I recently order the PowerBlock Classic Adjustable Dumbbell set from Amazon . I have be look for a set of adjustable dumbbell and do quite a bit of research on the various product out there . the Bowflex SelectTech and PowerBlock adjustable dumbbell set seem to be the most discuss product , by far -lrb- there be set make by other manufacturer that I do not consider -rrb- . aesthetically , the Bowflex SelectTech dumbbell look more like `` normal '' dumbbell to I than the PowerBlock Adjustable Dumbbell set , which look clunky in picture due to they boxy form factor . initially , I figure I would purchase the Bowflex SelectTech dumbbell . fortunately , there be a Sports Authority near my house that carry the SelectTech dumbbell and I be able to test they out in person . even though the Bowflex SelectTech dumbbell look really nice , they form factor be actually quite wide , which I think might limit some people 's range of motion when perform certain dumbbell exercise . they also feel really cheap to I . the `` unique injection-molded plastic '' coating on the dumbbell do not feel durable and the dial feel flimsy . who know ? I be sure there will be those who swear by they . I have never own they ; I only test they out for 15 minute in the store . after my experience test the Bowflex SelectTech dumbbell , I go back to the draw board and start do research on the PowerBlocks . in general , the review that I find on Powerblocks be very positive , although they boxy form factor still look really odd to I . the price tag on the classic powerblock dumbbell set be a bit less than Bowflex SelectTech dumbbell , which be a immediate plus , but I do not have the luxury of test they in the store . that say , I be able to find several helpful powerblock review on YouTube that give I enough information about they to feel comfortable buy they without test they . so I order the classic powerblock set , which go from 5 to 45 pound , enough weight for what I do . Amazon ship this product out to I in a timely manner and so far I have no regret . out of the box , these dumbbell be ready for use -lrb- no assembly require -rrb- . there be a one-page instruction manual that come with they -lrb- explain how to use the magnetic selector pin -rrb- . all in all , these dumbbell feel really solid . although they look really boxy , they actually feel very natural unlike the SelectTech dumbbell , which be so wide . unlike the SelectTech dumbbell , which require you to turn four dial to set the desire weight -lrb- two dial on each dumbbell -rrb- , the PowerBlocks only require you to slide in a magnetic selector pin to set the weight on each dumbbell , which make it faster to change the weight as a pair -lrb- two `` click '' as oppose to four `` turn '' -rrb- . I should say one thing about the magnetic selector pin on the PowerBlock ... it take I a little while to get use to it . when it be set properly you will actually hear the magnetic selector pin `` click '' into place . the pin actually work great ; it just take I a few time to get the feel . that say , if the selector pin ever break , you can purchase a replacement pin for $ 10 dollar through PowerBlock . who know what would happen if you break the dial on the Bowflex SelectTech ... although you do not need to buy a stand for the PowerBlocks -lrb- I buy the tray -rrb- , you should at least use a flat surface to change the weight -lrb- hardwood\/tile\/concrete floor would probably be fine -rrb- . I find it be hard to change the weight on carpet . the tray , however , help and be a relatively cheap docking solution . overall , I be extremely satisfy with the PowerBlocks . they seem very solid , and I believe that they be a great investment overall .