12 metric scale: length: 30 cm for both rulers. 6 scales in each ruler: 1:20, 1:25, 1:50, 1:75, 1:100, 1:125/1:100, 1:200, 1:250, 1:300, 1:400, 1:500. No need to waste time figuring out how to measure each increment. Solid Aluminum: Made of high quality aluminum, durable and anodized for corrosion resistance, not easily deformed. Thanks to the chamfered edges, there is no risk of accidental hits, scratches and cuts. Precision: the clean graduations and precise markings for supreme precision make the ruler professional. A perfect measuring tool for any architect, writer, engineer, teacher or student. Laser Engraved: The markings on the ruler are laser engraved for perfect definition. Very quick and easy reading without errors. These permanent marks and grooves will not fade or leave marks. Product Specifications Metal ruler (six scales for each): 1:100, 1:200, 1:250, 1:300, 1:400, 1:500/1:20, 1:25, 1:50, 1:75, 1:100, 1:125. Color: black. Types of technology: laser engraved. Material: anodized aluminum alloy. Features Supreme precision: The ruler measures approximately 30cm in length and has 3 concave sides with 6 of the most commonly used scales: 1:20, 1:25, 1:50, 1:75, 1:100, 1:125/ 1:100, 1:200, 1:250, 1:300, 1:400, 1:500. the white on black design makes reading very clear. Laser engraved markingsthe graduated ruler is precise, making your drawings, sketches and plans more precise.These markings do not fade and leave no marks so you can always see every increment clearly. Durable and reliable: High quality solid aluminum to prevent bending and warping. Usage: Suitable for architects, engineers, draftsmen, builders, roofers, teachers and students, etc. Also used for cutting, measuring, professional drawing, decoration, classroom and office.