Scale Ruler 30cm

The Helix 30cm triangular scale rule has 3 colour coded faces with markings of 1:1, 1:10, 1:2, 1:20, 1:5, 1:50, 1:100, 1:200, 1:500, 1:1000, 1:1250, 1:2500.Scale rulers are used by architects and engineers to calculate dimensions in a blue print or building plan without the use of time-consuming and complicated math equations.The ruler would be ideal for use in the office or at home.