Mr.T-Type Ruler Large (GT82)

From the package: "Mr. T-Square ruler is a tool for drawing right angle lines. You can hook the shorter scale side on the edge of the object, and you can check right angles or draw a line." Made of stainless steel.  

This version is a large size with a marking of 70mm and a length of 190mm. It is a highly versatile tool that can be used to cut large plastic sheets, etc.