With 7/8" Recess and Includes 10mm and 8mm Bolts. You may find more expensive bits but you will not find finer.Available in Position 1 and Position 2. Available in 3 Shape and Usage Varieties.#1 SMALL- 35mm Diameter (1 3/8") for smaller radius areas.#2- LARGE- 62mm Diameter (2 7/16") for use as a work horse to straighten and plumb vertical walls.#3- JOINT CLEAN UP BIT- 62mm Diameter ( 2 7/16") with slightly smaller bearing designed to remove 2mm of material to clean up ravels, spalls, crooked cuts and allow for a cleaner top surface along with straightening and plumbing vertical walls.Designed to operate on all routers up to 10,000 RPM. Optimal 1 bit speed 7,500 RPM for the small 35mm and 5,500 RPM for large 62mm.CUSTOM PROFILES AVAILABLE UPON REQUEST