pro : \* cheaper and space-saver compare to a set of 9 pair : 5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , and 45-lb \* upgradable to heavier weight -lrb- hear of this , but not yet confirm , and need to shop around -rrb- . however , 45-lb max be good for I for a long while for upper-body workout : arm , shoulder , and ab . for larger muscle group -lrb- i.e. chest , back , leg -rrb- , I use barbell . \* fairly compact compare to other kind of dumbbell -lrb- i.e. adjustable dumbbell with switching , screw , clipping , or 45-lb hex -rrb- \* look nicer than I think , and seem to last long \* tricep extension be very easy to perform , use the two corner handle , ... \* Rubber pad handle feel very comfortable on hand . con : \* unable to roll up in hand for forearm workout \* must handle with care -lrb- i.e. fixed dumbbell be more durable -rrb- . there be almost always pro and con . this con do not make I unhappy . love they . I wonder why they be not widely available in some local Sports Store . 4.5 star , half star be take off because of the con above . highly recommend .