Super steel blade trimmer, 15 types, shaft diameter 0.25 inches (6.35 mm), perfect for beginners. For use with 0.25 inch (6.0 mm) trimmer routers, we have included a collet zipper for 0.25 inch (6.35 mm) axis. The attached 0.25 inch (6.35 mm) collet chuck has been checked and inspected so that there are no items to fit in. Ideal for groove rolling, beveling, and decorative surface processing. Can be used with 6.0mm trimmer