Each Ready-To-Cut(tm) contains a roll of abrasive material which is pre-marked and color coded. Every Ready-To-Cut(tm) works with any Performax sander - simply find the color that corresponds to your drum size, and cut along the line. You'll save time and money with the Ready-To-Cut(tm), because it's guaranteed to have no breaks, no splices, and no seams, just perfect-fitting strips every time! Yields 28 wraps 10" (yellow line) 14 wraps on a 16 inch drum; 9 on a 25 inch; 10 on a 22 inch and 6 wraps on a 37 inch drum. You get a few less wraps in the 36 grit box then the 60-220 grits.