ROUTER BITGroove edges for T-moldings, splines or biscuits, and other purposes. Rout tongue-and-groove joinery. Slotting cutters are available with either 2-wing or 3-wing cutters. Each assembly includes a cutter, bearing for a 1/2" deep cut, and either a 1/4"-, 3/8"-, or 1/2"-shank arbor. Use in a handheld or table-mounted router. All assemblies include cutter, arbor and ball bearing.