The Faithfull Quick Roofing Square* also known as a layout or angle square, is designed to provide carpenters with a quick and accurate way to mark out for many building projects. It is widely used when constructing roof rafters. The square is manufactured from aluminium and has imperial graduations marked with degree measurements, which help simplify material layout and timber cutting. The Roofing Square is able to calculate hips, valleys and angles on roofs, making it a truly flexible square. Specification: Size: 180mm (7in).