5 tools in 1. This item can be used as a framing square, try square, miter square, angle finder, or a saw guide. The only portable framing square for 16" and 12" on center layout that can be used for all construction and measuring needs. This lightweight model is adjustable, portable, can fit in your toolbox, and includes an allen wrench to re-adjust the tool to a perfect 90 deg.. The all-aluminum construction product also has highly visible etched markings and comes with an instruction book.