Task Tools T24378 Keyhole Router Bit with 1/4-Inch Shank, 3/8-Inch by 3/16-Inch Carbide Height Keyhole router bit with 1/4-inch heat-treated, hardened steel shank; double flute for quick cuts Dynamically balanced up to 24,000 RPM to reduce vibration and kickback Non-stick powder coat finish reduces friction and resin build-up to protect from corrosion Premium quality Super Fine Grain Tungsten Carbide for an exceptionally smooth finish Size: 3/8-inch diameter by 3/16-inch carbide height