Description: Sturdy Combination Tri-Square: Well made of high quality stainless steel, anti-rust, durable and sturdy to use with Clearly and accurately calibration Easy To Read: 0-180 degree measuring range, Slotted and etched 12-Inch stainless steel ruler for easy reading Multifunctional Tool Kit: Consists of Depth, height and marking gauge, Center, square and protractor heads and Spirit level and scribe Fine Workmanship Finished with a bevel edged extension , roller knob and fine adjustment,great for measuring inner and outer angles of the parts Portable And Convenient: Featuring with handy and functional design, saving a lot of tools for measuring and making your workbench clean and tidy Specification: Material: Stainless Steel Overall Size ( L x H ): approx. 305mm x 120mm / 12 Inch x 4.72 Inch Color: Silver as shown in the display pictures Measuring Range: 0-180 degree Grading Value: 1mm Accuracy: 5' / 0.08 degree Package Includes: 1 Set of Combination Square Ruler Set Note: Calibration measurement should be zero, universal angle ruler zero, when Square are fitted with a ruler, and the bottom edge and the base Square foot in contact with the ruler without a gap, then the main scale "0" line aligned. After adjusting the zero position by changing the mutual position of the base scale, angle square, straightedge can test any angle within the range of 0-180 °.