This professional metric scale ruler is designed for architects, but is a wonderful tool for anyone needing a sturdy straightedge equipped with both metric and English measurements. This ruler comes in 12 inch / 30 centimeter length, in a triangular shape that helps keep the tool stable while drawing or lining. Scale reduction provided 1:20 / 1:25 / 1:33,33 / 1:50 / 1:75 / 1:100. The ruler comes in a neat, shockproof plastic tube. Maped has built a reputation as a company that is constantly on the cutting edge of design through intensive research in the areas of use and ergonomics.