Off white dimensionally stable plastic ruler. Precision divisions are numbered both ways. Dimension markings are in metric for easier working. Two coloured flutings. Ruler Type: Tri Ruler 4 Architect. 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.