chartpak 235e - triangular scale plastic 12 engineering color-coded
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.