PRECISION - The Woodpeckers SERX Straight Edge Tool is machined from aluminum to a tolerance of .0015" per foot. The laser engraved scales have a tolerance of ±.004" total accumulated error over the full length of the scale. FREESTANDING EDGE - The unique vee-groove profile on the base edge of the SERX gives your tool a solid footing, while maintaining a clear view of any high or low spots in the surface. MACHINE SETUP CHECKS - The woodworking straight edge is perfect for checking your table saw for flatness, making sure your jointer tables are parallel, setting up your router table & other machinery alignment jobs you might face. ADDITIONAL FEATURES - We laser engrave a bright white bar along the bottom edge that highlights low spots. The graduated rule edge is beveled at 30° to get the markings right down next to your material. MADE IN USA - Like all Woodpeckers products, the SERX Straight Edge Rules are precisely machined and carefully inspected right here in our Strongsville, Ohio, facility just south of Cleveland.