The part number for the 3 pack is 37448. Search for "37448 scotch brite" in google and you will find suppliers. The price is only about $3.99 for a 3 pack, as apposed to $20 for a box of 20.

The thing is they are labeled as "Fine" on the package, but are indeed Ultra Fine, and are listed as Ultra Fine in the 3M book.

I found mine at a local paint supply shop, but have since located them online.

I posted this to a new thread so it can easily be seen by those doing a search for Ultra Fine Scotch Brite in the future.

Lance