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.