This spiral router bit has an up-cutting action that pulls chips up and out of mortises, slots, and holes. Ideal for deep cutting applications where good chip clearance is a must. The spiral shape provides a shearing action for extra smooth cuts - regardless of grain direction. Solid carbide and double fluted. Made by Whiteside. USASpecificationsSH = Shank Size. CD = Cutting Diameter. CL = Cutting Length. OAL = Overall Length.1/4" SH X 1/4" CD X 1" CL x 2-1/2" OAL