I gulped at the price of these 4 precut pieces of sandpaper, but after having issues with my own cuts on the paper, I decided to try them once. They work as advertised and the only downer I have with them is, that they are expensive. Also wish there was a mix of different grits to choose from, instead of 4 of the same each each grit level.
I have a Ryobi thickness sander and these fit perfectly. They attach exactly the way it was designed and they work great. I'm a luthier and often have to sand pieces down to 1/16 of and inch so I need this tool to work well so I was very happy that the machine works so well with these strips.