I get sleeves at Grizzly.    https://www.grizzly.com/products/grizzly-1-1-2-dia.-x-5-1-2-hard-sanding-sleeve-a80-3-pk./h6670

Look around, they have several sizes, but they are not organized very well.

They also have longer sleeves that could be cut down.

Work your fingers to the bone,what do you get? - Boney Fingers. Hoyt Axton