It is a stainless steel blade used to measure lengths, with scales divided into units of the metric system and the English system.
The graduated ruler is used when the measurement accuracy does not need to be less than one millimeter in the metric system or thirty-two grand per inch in the English system.
Measurement with graduated ruler can be made with reference back or without backrest.
There are rulers of various sizes, however the most common are those of 150mm or 6 inches and those of 305mm or 12 ".
