Industry-standard Alvin and Alumicolor wooden drafting T-squares have blades made of selected hardwood to offer strength and rigidity. Durable, see-through acrylic plastic edges are elevated to prevent smudging and eliminate surface scratches. Alumicolr calibrated T-squares feature graduated edges in customary and metric measurements. Perfect for drafting, drawing, layout, and more. Professional wood T-squares are great for schools, suitable for professionals and students alike.