Premium Aluminum Alloy : Crafted from premium aluminum alloy , this carpentry square balances lightweight design with rugged durability , resistant to deformation for frequent professional use Double Size Versatility : Includes 7 inch and 4 inch models , ideal for engineering drafting , woodworking layout , roof angle measurement , and other applications Precision Etched Markings : Features etched scales for clear visibility , imperial on the front , metric on the reverse , with a conversion table on the ruler surface for instant measurements and reading Multifunctional Tool : Functions as a protractor , bevel gauge , marking saw guide , framing square , and ruler , essential for construction , renovation , and furniture crafting Size Details : 7 inch triangle ruler : 7×7 inch (18.5×18.5 cm) , 4 inch triangle ruler : 4×4 inch (11.5×11.5 cm), Manufacturer: PATNFR