Our 180mm Metric Rafter Square has a strong reinforced frame and provides the user with a high degree of versatility. Scribe notches from 25mm-145mm allow you to easily and accurately make precise measurments for cuts. A 25mm cutout in the rafter square helps prop pipe allowing you to cut it more easily on the job site. A reinforced frame gives you more durability on the job site while high visibility laser etched markings make the rafter layout square easier to read.