Uxcell a14101300ux0139 Silver Tone Blue 1/4" x 7/8" Core Cove Box Router Bit for Woodworker Product Name : Cove Box Bit; Standard : 1/4" x 7/8";Shank Diameter : 6.35mm / 1/4" Cutting Diameter : 22.2mm /7/8";Cutting Radius : 11.1mm / 7/16" Cutting Depth : 14.3mm / 9/16";Overall Length : 45mm / 1.8"