Application: For Flex-Loc TS Surface Blending Discs Molded rubber pad with a 1/4" steel shank for quick mounting. Compatible with Standard Abrasives Quick Change attachment system. Hard density for aggressive cutting action. Medium density for all purpose applications. Soft density for contours and fine finishing work. Unique locking device on face provides convenience and quick change. For Flex-Loc TR Surface Blending Discs Molded rubber pad with a 1/4" steel shank for quick mounting. Compatible with a 3M Roloc attachment system. Medium density for all purpose applications. Unique locking device on face provides convenience and quick change.