These are simple tools that are always useful. The Standard Set has five drum sizes from 1/2 x 1/2" up to 2 x 1-1/2". It has Quick-Lock fittings on each shaft speed up sleeve changes. The Extra Long Drum Set has four drum sizes from 1/2 x 2" up to 1-1/2 x 2". It uses a standard hex nut locking method.
Every drum in both sets comes with one fine and one coarse grit sleeve. Replacement sleeves (fine, med and coarse) are available in packs of 3 each grit for each size (9 sleeves per pack).