Precision-edged for accurate measuring. Open face number design is easily legible. Made of durable laminated plastic. Packed in reusable plastic case. Color coded, 10; 20; 30; 40; 50; 60. Ruler Type: Triangular Scale; Length: 12 in; Standard Scale: 10 in; 20 in; 30 in; 40 in; 50 in; 60 in; Metric Scale: N/A.