High quality material: the metal scale ruler is made of high quality aluminium alloy and is anodised. It has corrosion resistance and is not easy to deform and fade. The surface is smooth, the lines are smooth and it is convenient to use.NO SHARP EDGES - Our triangular scale rulers have bevelled edges, so no accidental scratches and cuts. With fine workmanship, smooth edges, no burrs and chamfer and does not hurt your hands, specially designed for your safety.LASER ETCHED MARKINGS - Triangular scale aluminum markings are for a perfect. Very quick and easy to read without making mistakes. These markings and permanent grooves will never fade or smear.6 Metric 30cm Metric Ruler: Contains 6 commonly used scales: 1:100, 1:200, 1:250, 1:300, 1:400, 1:500. No need to waste time finding out how to measure each step. Our triangular scale ruler is easy to use and understand regardless of your profession or skills.Widely used: the multi-functional metric ruler can be used for cutting, measuring, professional drawing, decoration design, classroom and office purposes. The perfect measuring tools for architects, designers, engineers, teachers and students.