1、Sturdy Aluminum Construction: Made from excellent rugged aluminum material, this triangle drafting ruler minimizes bending and warping. Its robust design allows for a flat placement on drawing surfaces, ensuring accurate positioning for accurate measurements and lines. 2、Concave Design: The architectural scale ruler features a unique concave design that helps reduce smudging, enabling the creation of clean and distinct pencil lines. This design is suitable for detail work, ensuring that your drawings are crisp and professional looking. 3、Accurate Scale Options: With accurate scales of 1:100, 1:200, 1:250, 1:300, 1:400, and 1:500, this triangular scale ruler offers a versatile range of measurement options. This allows engineers and architects to make accurate calculations quickly and efficiently, catering to various design requirements. 4、Professional Grade Tool: Suitable for architects, draftsmen, engineers, and students, this engineer scale ruler is a professional grade tool renowned for its high accuracy. It is widely used in architecture, drafting, and engineering applications, making it an essential item for anyone in the field. 5、Accurate Markings: The etched markings on the architect scale ruler ensure that the scales never fade, providing long lasting accuracy. Unlike printed or painted markings that can wear off, these permanent engravings guarantee that your measurements will remain clear and stable over time. Item Type: Architectural Scale Ruler Material: Aluminum Use: Architectural scale ruler is a professional tool with high accuracy. Triangle ruler is widely used in architecture, drafting, engineering, school. This ruler is a good tool for architects, draftsmen, engineers, and students. Range: 30cm 1 x Architectural Scale Ruler 1 x Storage Box