Kinex Precision Ultralight Precision Square 60 mm x40 mm

This precision square is made by Kinex to Accuracy Class 0 according to DIN 875/0.  Their accuracy is several times better than many other high accuracy woodworking squares.  These squares are made of titanium and carbon fiber which makes them very light and corrosion resistant.  

60 mm x 40 mm, with 16 mm wide x 3 mm thick blade, and 16 mm wide x 9 mm thick base.  Accuracy Class 0 to DIN 875 is equivalent to a squareness of better than 0.007 mm (0.00028") along the entire length of the square.