The Faithfull Prestige Tri-Scale Engineer and Architect Rules are commonly used to convert ratios with scales when making precision drawings. This model features 6 scales that can be easily recognised thanks to the colour coded inserts. The unique triangular profile keeps fingers away from knife blades when used for cutting or scoring card etc. This heavy-duty version is manufactured from aluminium using computer numerical controlled (CNC) machines. The black anodised finish offers enhanced corrosion protection and the laser engraved scales give outstanding measurement accuracy. Manufactured to the highest standards and covered by a 10 year guarantee.This Faithfull Prestige Tri-Scale Architect Rule has the following specification: Length: 300mm (12in)Scales: 1:5, 1:10, 1:50, 1:100, 1:200, 1:500