Easy Wood Tools 4&rdquo; Diameter x 1&rdquo; x 8 TPI Precision CNC Machined Anodized Aluminum Faceplate with Set Screws, 8 Large Mounting Screw Holes, Spanner Hole F440 100% designed and CNC precision machined in the USA 1 x 8 TPI threads 4 overall diameter Solid anodized aluminum, so wont rust or stain and minimizes tool damage if struck Low profile (12 thick plate) to reduce vibration 8 Large countersunk mounting holes and 5/16 spanner hole