The popular Keller templates require the use of bits with shank-mounted pilot bearings, this bit is specifically designed for use in the Keller system, #45880, diameter (D) 11/32, angle (a°) 7°, cutting height (B) 3/8, shank (D) 1/4, overall length (L) 2-1/4, Type Dovetail, replacement bearing 47712, Keller number 1631/1531, flutes 2, Carbide Tipped Keller Dovetail 7 deg x 11/32 dia x 3/8 x 1/4 inch shank with upper Bb