Dumbbell weight extender

These dumbbell extender brackets are glued onto dumbbells and allow you to add additional weight to the dumbbell using Olympic barbell "change" plates.
the extender brackets use magnets to hold the additional plates in place

I had a problem that I needed some dumbbells in between the 20 pound and 35 pound ones I own.
I have some small barbell "change" plates and I devised this extender bracket to hold the small plates (1 1/4 , 2 1/2 and 5lb ) plates onto the 20 pound dumbbell

I print