The Whiteside 2910 Rounding Over Undermount Router Bit is useful for softening or rounding under the upper edge of solid surface materials up to 1/2" thick when undermounting sinks. Tip mounted nylon bearing exactly follows the shape of the material. Carbide tipped. Double flute. This bit comes with a BB300 (3/16" ID x 7/8" OD x 10 deg. bevel) bearing. Whiteside Machine Company - Claremont, North Carolina. Specifications SH = Shank Size. OAL = Overall Length 1/2" SH X 10 Degree X 3" OAL