Hi I am an American inventor check out my Modified Square Tool made in USA Pittsburgh PA. The Modified Square is a multi squaring tool with six squaring tools in one square. Regular Square, Tri Square, Combination, Centerhead Square, (3points of centering) 2x4 notchout design, zero/zero centter finding rule. The Modified Square Tool new square on the block measures heights and depths simultaneously, stairstringer square, many capabilities.in many different fields.