Lymans Brass Smith Die Wrench fits all Lyman die nuts, including die body, expander plug, seating screw, and decapping rod lock nuts. This includes the 1 lock nuts used on our Pro dies as well as Dillon dies. Made of rust resistant stainless steel, the closed end design offers added strength with thinner side walls allowing easier fit between dies. The 5 openings accommodate the following size nuts: