This 300mm Triangular Scale Rule by Helix is made from hard-wearing plastic and features a colour-coded system to help to differentiate between scales.
Each side is 2cm wide and is ideal for students as well as professionals.
The Scales included are: Red: 1:100, 1:200, 1:5, 1:50 Blue: 1:2, 1:20, 1:10, 1:1 Green: 1:1250, 1:2500, 1:500, 1:1000