My Fein 6' RO sander is a great tool, but there aren't a lot of options when it comes to getting abrasive disks that fit it. Fein makes excellent disks, but they're too expensive for me. These disks are a consistent good quality, at a fraction of the price. Yes, it probably takes three of these to do the work of two Fein disks, but they are less than half as expensive, so the math works. I recommend them highly.