When you need to setup a machine, mark accurate layouts, do some drafting or checking straightness of your work piece for warping, this precision straight edge is the essential tool you need. The 5.00mm hardened steel blades are meticulously ground and lapped for straightness and parallelism, and they have a beveled knife edge with imperial 1/64in scales, which means they can be used as precision rulers. For storage they have a hanging hole as well as a protective case if you prefer to store them in a drawer.
All the straight edges are accurate to 0.025mm over the length of blade, so that means the longer length you choose, the more accurate it is over the length of the blade in sections.
As you will note in the photo of us using the straight edge to set up the jointer knives you will see it picks up a dished outfeed table on the machine.