I have research all the adjustable dumbbell out there and have find powerblock to be the smallest , sturdiest most dependable . I be worry about the BLOCK design but after use they for every exercise I can think of , they work flawlessly -lrb- even tricep extension -rrb- . I didnt ' buy the stand with they , I use a older chair to place they on during workout . they take up little to no room at all and be much cheaper than buy a complete set of dumbbell . I highly recommend they !!!