Sold as 1 Each. Plastic. Numerals and graduations are sharply delineated. Center section magnifies one line at a time. Imperial and metric measurements. Edges are straight and true. 1 edge ruled in 1/16' scale, the other centimeters. 15'. We work carefully everyday to make sure our products measure up. Magnified portion ruled on side in 1/16', the other in tenths. Westcott has been a trusted name in rulers since 1872. Clear, easy to read.