We have a set of adjustable dumbells but I'm not sure if they're Probell. Ours are adjustable from 5-50 pounds per dumbell in multiples of 5 pounds (so 5, 10, 15, etc.) depending on where the pin is positioned. To get 10, 20, 30, etc. all you do is move the pin - that's easy. To get the 5, 15, 25, 35, 45 weights, you have to remove the 2 metal cylinders from inside the weight (e.g. to get 15 pounds, position the pin to the 20 pound level and remove the 2 cylinders). To get 7.5, 17.5, 27.5, 37.5 and 47.5, you remove just 1 metal cylinder. Each cylinder weights 2.5 pounds. We also have 2.5 pound platemates which are just magnetic weights that attach to the side of the dumbbell. We use these to get 22.5, 32.5, 42.5 pounds.
The only weight I can't get with our adjustable dumbells is 12.5 pounds. This is because at 10 pounds the dumbells have a plastic side so the platemates will not attach. At 20, 30, 40 and 50 pounds you have metal sides. I purchased a set of 12 pound dumbells that I use instead.
I know this sounds confusing to someone who's never seen what these things look like. The look and feel is quite different from regular dumbells. They are rectangular shaped and you stick your hand inside the dumbell so it feels a little confining at first. Picture sticking your first through a small hole inside a child-sized shoebox and that's about what it looks like.
The advantage of using adjustable weights is the cost (cheaper than buying multiple sets of dumbells) and reduced storage space. The drawback is the time it takes to adjust the dumbells for different weights. For Cathe's weight tapes, I usually end up pausing the tape to give me extra time. You get pretty quick at adjusting these once you get used to them but this is something to keep in mind.
Hope this helps!
