300/400mm Aluminum Alloy Woodworking Marking T-Rule Marker Square Hole Marking Precision Marking Ruler Measurement OOTDTY Hole Positioning Marking Ruler Suitable for Woodworking Marking > Aluminum alloy material: The ruler is wear-resistant, rust-proof, and has clear scales. TS-400 Length: Approx. 400 mm / 15.7 inches TS-300 Length: Approx. 300mm / 11.8 inches Main scale thickness: 8.5mm / 0.33 inches Backing thickness: 16mm / 0.63 inches Instructions > Find the hole corresponding to the scale and insert the pencil into the hole. Move the ruler to draw the lines you need. (Each hole represents 1mm, the distance between two holes is 1mm). Packing list: 1 * Precision marking T-rule 1 * Screwdriver