Rub collar for 3/4" Arbor only!, #940, (D) diameter 2-1/2, (D), ore 1/2 & 3/4, (b) Cutting height 1-5/16, (r) radius 5/16, D1, 3-1/8, D2 1-7/8, Optional rub collar c-008, c-016, 940 2-piece carbide Tipped 3-wing stile & rail concave cabinet door 2-1/2 dia x 1-5/16 x 5/16 radius x 1/2 & 3/4 Bore set for 1-5/16 material