Scale Rulers (Triangular Type) 30cm

Scale Rulers (Triangular Type) 30cm
 
Scale rulers are made in triangular form so that they can be marked with different scale ratios.
A triangular scale has 6 different ratios on it.
No.1 1:20, 1:25, 1:50, 1:75, 1:100, 1:25
No.2 1:20, 1:25, 1:33 1/3, 1:50, 1:75, 1:100
No.3 1:2.5, 1:5, 1:10, 1:20, 1:50, 1:100
No.4 1:100, 1:200, 1:250, 1:300, 1:400, 1:500