The 7 Magnetic Rafter Square has a stronger frame and is the most versatile rafter square. The rafter layout square features scribe notches from 1 - 6 allowing you to easily and accurately rip lumber. A 1 cutout in the rafter square helps prop pipe. making it easier to cut the pipe on the job site. A reinforced frame gives you more durability. while high visibility laser etched markings make the square easier to read.