: Architectural ruler is durable, and solid high quality aluminum can reduce bending and warping. Multipurpose: Suitable for architects, engineers, draftsmen, builders, roofers, teachers and students, etc. Also for cutting, measuring, professional drawing, decoration design, classroom and office use. -friendly: It has 3 concave sides with 6 different scales, laser etched markings and can be marked with precision. It can make your and drafts more accurate. Again, these markings ' fade or smear, so you'll always see each step clearly. Attractive: The scale ruler is lightweight, rustproof, perfectly balanced, durable, and it has laser-etched markings with a sleek black finish. In addition, it is easy to read measurements and easy to carry. Material:aluminum colour:Black Package Contents: 1 x ruler Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.