take I a few minute to learn how to quickly change the weight and use the pin , but after that I be good to go !! I mean these be exactly what you need if you want a convenient set of dumbbell you can use with any workout program . I use these for p90x and have no complaint . you cant obviously use these to do `` every '' exercise because of the shape , but come on ... you have the flexibility to go from 5-45lb ! I just use band for exercise that require more wrist freedom . not a big deal at all !! so far I love these ! I would recommend they to anyone who be serious about get in shape at home or away from the gym !!