The Triangular Scale Ruler T4 Isomars  has colour coded sides of red and yellow in the following scales:

• 1:10,1:20,1:25,1:30,1:40,1:50,1:100,1:200,1:250,1:300,1:400,1:500
• Dimensions are in (cm) and (m) for easier working.
• Scale rulers are used by architects and engineers.