Trimming Router Bits are made by Amana Tool, the leading manufacturers of high quality wood cutting tools. Amana Tool 45489-S Carbide Tipped Dado Clean Out 1/2 D x 1/8 CH x 1/4 Inch SHK w/ Upper Ball Bearing Router Bit is useful for template/pattern routing of parts, joints, and internal cuts, and can be used in hand-held and table-mounted routers. SPECIFICATIONS: Diameter (D): 1/2; Cutting Height (B): 1/8; Shank (d): 1/4; Overall Length (L): 1-3/4; Replacement Collar: 47724; Replacement Bearing: 47701; Flutes: 2.