Diablo, 4-1/2", x-lock, diamond continuous, masonry, cut off disc, diamond continuous rim masonry cut off discs provide extreme durability, minimal downtime & increased productivity, 4x longer cutting life versus a standard diamond cut off disc, industrial grade diamonds with hardened disc body delivers lasting durability & maximizes cutting quality in hardened materials even in extreme applications, designed to be backwards compatible, these discs work with x-lock angle grinders & 7/8" arbor angle grinders.