I really like this product because it be compact and not as cumbersome as the larger set . for most people , this will suit they need and they can get a upgradable set later on . the small size allow almost everyone to perform conventional exercise with proper form . with the larger PowerBlocks , this be a concern because of add bulk and length . the square shape of these dumbbell allow the manufacturer to put more weight in a smaller place . this make these much smaller than other round adjustable dumbbell over the same weight range and increment . from a safety perspective , I also think these be the safest and most rugged adjustable dumbbell . however , this do not mean that nothing can go wrong . you need to be conscious of insert the pin straight across and the pin mechanism right side up so the magnet engage to hold the pin together . there be a also a backup elastic band to prevent a plate from fall , but this might not save you in a overhead triceps extension . this product be rugged and well make . it be less likely to break then some other brand and the concept be simple behind how the adjustment work . in other word , there be less thing to break or go wrong and I believe these can take a fairly hard fall and still be fine . I have not drop mine , but I base this assumption on the way they be design and the quality of the material and how they be put together . I would definitely purchase these if you do circuit training and want to keep you pulse up . if you become serious , you can buy a expandable set over a larger range later . this be great entry point product .