Check the listing for details. Folding and Straight Ruler Kit 30/15cm Aluminum Plastic Ruler, Black/Blue. Color: Black, Condition: New. Listed at 11.23 USD. The folding ruler is made of aluminum alloy, which makes it anti-rust, anti-corrosion, the office ruler is made of durable PC plastic and aluminum alloy which is hard and durable, not easy to deform or damage, ensuring measurement accuracy.The folding ruler adopts a center rotation design, ensuring stable rotation for precise angle measurement and drawing. The clear angle scale allows intuitive reading, minimizing errors and improving efficiency. Its folding design saves space for easy portability and storage. The dual-material ruler features a chamfered design on both edges for smooth handling, making it a functional tool for drafting and everyday use. The aluminum alloy component is durable and wear-resistant, while the PC resin material offers high transparency for easy viewing and drawing.