307900
Triangular Reduction Scale - 1 1:5, 1:10, 1:20, 1:50, 1:75, 1:100, 1:125 30 cm metric
318931
Triangular reduction scale - 10, 20, 30, 40, 50, 60: inch 12 in
318949
Triangular Reduction Scale - 1:100, 1:200, 1:250, 1:300, 1:400, 1:500 30 cm metric