This 12 (300mm) Rafter Angle Square boasts a solid Aluminium Alloy body giving accuracy and durability for any job or worksite The thick edge is useful as a saw guide. It can be used directly with the saw against the square for cross cuts or angled cuts using the stamped protractor scale. It can be used indirectly as well, using the scribing notches to create a saw cut line for rip cuts   The Squares integrated distance and angle scales let you quickly and accurately mark your cut lines on your stringers Scales for cutting hip, valley and jack rafters For roofs, solar panel supports, stairs, cabinets trim work and many other layout projects The rafter scales are laid out mathematically to avoid time consuming calculations Permanent graduations with easy-to-read numbers Continuous scribing notches ideal for ripping at 3-1/2 and 5-1/2 2x4 board dimension markers for measuring 1-1/2, 3 and 3-1/2 Low-glare protective powder coated finish