Timberline 420-61 Carbide Tipped Reversible Ogee Window Sash & Rail 1/8 R x 1-3/8 D x 43/64 CH x 1/2 Inch SHK w/ Center BB Router Bit Carbide Tipped 1/2 Inch Shank SPECIFICATIONS: Diameter (D): 1-3/8 Radius (R): 1/8 Cutting Height (B): 43/64 Shank (d): 1/2 Overall Length (L): 2-3/4 B1: 5/16