I bought a Porter Cable 333 with hook and loop base. When the hooks died I went to replace it witha PSA pad, and PC wanted $25 US. Our local big box hardware store had a Ryobi base for about $10. The hole spacing was wrong and it has 5 holes instead of 8, but I took it home anyway. I drilled and counterbored new screw holes, use Brand X 5-hole paper, and it has worked fine for 4 years.