TRACER 12" ProSquare Adjustable Measuring Tool (Professional Construction Square with lockable arm and easy to read laser markings)

Amazon

12'' SQUARE TOOL - The TRACER 12'' ProSquare is a quick and simple square tool offering a true 90° angle, with added design benefits and guides making it the ultimate square tool on the market. CONSISTANCY AND REPEATABLITY - Coming equipped with a lockable arm, set to the desired angle and achieve precise, consistent cuts. LASER ETCHED MARKINGS - The TRACER ProSquare includes easy to read Com & Jack Scale markings as well as Hip & Valley Scale markings. All markings are etched with a laser to ensure that the markings don't fade over time. MACHINED FROM SOLID ALUMINIUM - Being made of solid aluminium allows the TRACER ProSquare to be robust while remaining lightweight and precise for the user. INTEGRATED RULER - The TRACER ProSquare comes with an inbuilt 0-170mm ruler along the ‘plumb’ edge for swift and easy measuring.

ManoMano

The fastest and simplist tool for marking out com, jack, hip and valley cuts.COM & JACK SCALE - Set scale to match the pitch of the roofHIP & VALLEY SCALE - Set scale to match the pitch of the roofCOMMON 1 90 SCALE - On outside edge for all other angles, cuts and marksFeatures:Easy to read scale markingsTrue 90 angleLockable arm, either set to desired angle or set to zero and use as a normal quick squarePre-marked 1/3rd of width of timber for seat cuts0-260mm ruler on plumb edge, with 5mm gradations for marking parallel lines