The popular kellera templates require the use of bits with shank-mounted pilot bearings. This bit is specifically designed for use in the kellera system., #45890, diameter (D) 1, angle (a°) 14°, cutting Height (B) 1, shank (D) 1/2, overall length (L) 2-3/4, Type Dovetail, replacement bearing 47738, Keller number 3637, flutes 2, Carbide Tipped Keller Dovetail 14 deg X 1 inch dia X 1 inch x 1/2 shank with upper Bb