Professional 30cm 12" Metric Triangular Aluminum Metal Scale Ruler 1:10 1:20 1:25 1:30 1:40 1:50 / 1:100 1:200 1:250 1:300 1:400 1:500 in a Case Scale 1:10/100 1:20/200 1:25/250 1:30/300 1:40/400 1:50/500 Length: 30cm Made of silver aluminium with black letters and silver, green and red coloured slots. High quality item supplied in rigid transparent plastic case. Ideal for Architect, Engineer, Surveyor, Building Services Consultants, Craftsmen.