CTA Tools 2319 Engine Hone Replacement Stones for CTA Models 2325 and 2310, Fine Features a Set of Three (3) Stones with Cotter Pins Fine Grit - 400 and 3-Inches in Length For Use on CTA Tools 2325 and 2310 Engine Cylinder Hones Fits Most Other Major Brands Heavy-Duty Construction Allows for Strength and Durability