High quality material: Roofing triangular protractor is made of aluminum alloy, anti-corrosion and anti-rust. The surface is matte black and smooth, which can avoid glare, and the scale is clear and easy to read. High Accuracy: ametric and inch measurements, the scale is clear and accurate, with 0-90 scale, stamped inch scale and ordinary conversion chart, easy to measure and read.Multiple Functions: Triangle ruler can be usedas a protractor, miter, saw guide, line marking, three meter square, frame square and ruler.Multi-use: The thick edge of triangular metric ruler can be used as a saw guide. The engraved protractor can be used withthe saw against the square for cross or oblique cuts.Applications: Aluminum carpenter square can meet the needs of hobbyists, home builders, fabricators, DIY enthusiasts and artists, as well aswoodworking.