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 2 Only.Designed to operate on all routers up to 10,000 RPM. Optimal B bit speed 7,500 RPM to 15mm, 7,000 to B-20 & 6,000 for B-30.The Single breaker bit is a terrific addition to this profile for speed and bit longevity, use first for all sizes to save shape on Position 1 Bit.CUSTOM PROFILES AVAILABLE UPON REQUEST