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., #45882, diameter (D) 7/16, angle (a°) 7°, cutting Height (B) 3/4, shank (D) 1/4, overall length (L) 2-5/8, type Dovetail, replacement bearing 47712, Keller number 1633/1533, flutes 2, Carbide Tipped Keller Dovetail 7 deg X 7/16 dia x 3/4 x 1/4 inch Shank with upper Bb