Details
Machinist Square Precision Engineer Wide Seat Square 90 Right Angle Ground Hardened Steel Angle Ruler 7.9 x 5 Inch

Precision: DIN 875 Grade 1,designed for precision layout,machine set-up and laboratory use.
Squares are true right angles both inside and outside.
These squares are made of hardened, tempered and polished steel,beams and blades are ground and polished for parallelism;The blade is permanently fixed to the beam by means of tapered self locking rivets which ensure complete rigidity.
7.9 inch blade and 5 inch beam,length of blade is measured from corner edge of beam to end of blade.
The small plastic case it comes with makes sure that it will always remain THE standard of square for you from now on.