Johnson's 7 in. Johnny Square is a solid die cast aluminum rafter angle square with CNC computer machined edges for impressive accuracy and durability. Its permanent graduations and numbers are easy to read, featuring 1/8 in. scribe notches from 1 in. to 5 1/2 in. The scribing notches allow this tool to be used for fast and accurate measurements when making rip cuts, which are common cuts on every job site as tradesmen seek to convert different widths of lumber to their specific needs. This square helps ensure quick and easy angle cuts and is great for use with rafters, roof layouts, stair layouts and more.