Solid 7" aluminum body with CNC (Computer Numerical Control) machined edges for greater accuracy and durability. Permanent graduations and numbers are easy-to-read. Thick edge is useful as a saw guide. 1/8" continuous scribing notches - ideal for ripping at 3-1/2" and 5-1/2". Low-glare, protective powder-coated finish. Complete instruction manual included with rafter tables.