Helix Architects Scale Ruler - This Helix ruler is a stylish scale ruler suitable for architects - The Helix architects technical scale ruler has marking of 1:1, 1:100, 1:20, 1:200, 1:5, 1:50, 1:1250 & 1:2500 - Scale rulers are used by architects & engineers to calculate dimension in a blue print or building plan without the use of time consuming & complicated math equations - The ruler would be ideal for use in the office or at home What's in the box Scal Ruler