1、Standard: The scale is clear and scratch free, in line with international standards, high accuracy measurement and accurate spacing, practical and beautiful. 2、3 Sizes: This engineering ruler has 3 sizes of 15cm, 20cm, and 25cm, suitable for enthusiasts who love computers, electronics, and electricians. 3、Metric And Inch Measurement: The ruler includes basic functions such as measuring metric and inch sizes, drawing lines, and measuring angles. 4、Multi Function: It also integrates the commonly unit SMD components standard package, line width size reference, drilling size reference used in drawing PCB. 5、High Quality Material: Fine workmanship, the ruler is made of gold plated PCB material, high hardness, good wear resistance, and durable. 3 x Engineering Ruler Item Type: Engineering RulerMaterial: PCBProduct Specifications: Approx. 15cm/ 5.9in, 20cm/ 7.8in, 25cm/ 9.8inColor: Black Gold PlatedRange: Metric: Approx. 15cm/ 5.9in, 20cm/ 7.8in, 25cm/ 9.8inInch: Approx. 6in, 7in, 8inCommonly Used Line Width Size Reference:8mil, 10mil, 15mil, 20mil, 25mil, 30mil, 40milCommon Drilling Reference Size:Approx. 1.0mm/ 0.04in, 1.5mm/ 0.06in, 2.0mm/ 0.08in, 2.5mm/ 0.10in, 2.5mm/ 0.10in, 3.0mm/ 0.12in