IRWIN Tools Rafter Square, Hi-Contrast Aluminum, 7-Inch (1794463) This professional tool has permanent deep stampings are durable. The aluminum body is rust-proof and weather-resistant The square has multiple scales: 1/8-, 1/10-, 1/12-, and 1/16-inch Features rafter tables, brace and octagon scales and Essex board measure Yellow markings on blue background are easiest to read