The 50cm/20 Inch Metal Ruler (243.PA008) is a rigid metal ruler with a double scale in centimeters and millimeters on one side and in inches on the other, making it useful for measurements in both metric and imperial systems. Unlike a plastic ruler, metal does not bend or break easily, maintaining a straight line even after intensive use or when used as a guide for cutting with a craft knife or utility knife. The 50cm length is suitable for drawing longer lines than a common school ruler allows, making it useful for both technical drawing and manual work requiring precise cuts. It is suitable for offices, schools, technical drawing, and craft workshops where a sturdy ruler and precise guided cutting are needed. The engraved scale remains legible even with repeated use of the craft knife on the ruler.