Our 30cm rulers, are made from a lightweight plastic, and don't have the sharp edges like steel verions. Used by geologists, miners, surveyors architects, these premium rulers are triangular to allowing up to 6 different scales to be viewed on each ruler. The ruler has been designed with grooves along the central line to allow easy holding whether your in the office or out in the field.
Our most popular used by most Geologists is the TRIR-04 Scale Rulers.