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.

You don't always get what you go after,but you do get what you wouldn't have got if you didn't go after what you didn't get. Blaze Foley