These sets include two trim cutters for stock 7/8" Through 1" In thickness. (These trim cutters can be removed for making bearing-guided cuts on stock Under 7/8" Thick.) USE in a table-mounted router. Guide straight cuts with the fence, setting it tangent to the trim cutters. Use the pilot bearing Only for cuts on curved rails or stiles; for cuts on curved parts 7/8" To 1" Thick, a template must to used, #55420, diameter (D): 1-5/8, radius (r): 1/4, cutting Height (B): 1-1/16, Shank (d): 1/2, overall length (L): 3-5/16, type: concave, replacement bearing: 47708 (2), flutes: 2, C: 3/8, 55420 carbide Tipped 2-piece concave stile and rail 1-5/8 dia x 1-1/16 x 1/4 radius x 1/2 inch Shank set