Lyman’s handy tool cuts a chamfer on the inside and the outside of the case neck to deburr the case after trimming and provide a gentle transition at the mouth to help start the bullet for seating. The tool is made of hardened steel for years of trouble-free service. The standard tool fits .17 through .45 calibers, while the extra-large tool is designed to handle any case all the way up to .60 caliber.