A 60 grit and 100 grit combination aluminum oxide 3 x 21 sanding belt for hand sanding blocks.
Let's say you are fixing up an old car and need to sand down that last layer of Bondo. This ComboBelt would be a good choice for forming and shaping the area before finish sanding.
Hand sanding operations are by nature labor intensive. One way to speed things up is to eliminate certain unneeded procedures. Changing grits or walking back to get a different grit are things that could be eliminated using ComboBelts.
These belts consist of two separate pieces of high quality sanding belt material, each of a different grit and bonded together to form a continuous 3 x 21 sanding belt. ComboBelts provide a different grit on the top and bottom surfaces of your sanding block making it possible to sand down a rough surface with the coarse grit then flip the sanding block over and finish sand the area with the fine grit without having to take that extra step, now that's convenience.
Keep your ComboBelts dry. They will not withstand getting wet in any way.
ComboBelts are designed for QuickSander sanding blocks, not for belt sanders.