The Performance Tool replacement stones are built to last and provide reliable performance for a variety of sharpening tasks. Made with high-quality aluminum oxide material, these stones offer versatile applications and are designed to fit the Performance Tool item W193C. With fine, medium, and coarse grits, these stones provide precise grinding to help restore a sharp edge to dull blades. Installing these replacement stones is easy, simply remove the old stones from the W193C sharpener and replace them with the new ones for hassle-free installation. This 3-piece set offers great value for money, giving you the convenience of having replacement stones on hand whenever you need them, without breaking the bank.