1Dual Layer Design: This double triangle ruler adopts double layer design, with 9mm thickness, each with metric scale on one side and imperial scale on the other side respectively, to meet your different needs. 2Multifunctional: This triangle square rafter tool is multifunctional to keep your projects square and level, providing you with accurate, high accuracy results for architectural drafting design, carpentry and more. 3Excellent Aluminum Alloy Material: This woodworking square ruler is made of excellent aluminum alloy material and is anodized for high hardness, rust and erosion resistance. 4High Accuracy: This accurate carpentry square tool has a clear calibration, which can reduce errors and ensure high accuracy measurements. 5Wide Application: This aluminum alloy triangle ruler has a wide range of applications and can be used to hold boxes, picture frames, etc. to assist in the square making process.