PeriMeter

This is a rotary measuring device that can easily fit into an EDC lineup and can quickly and accurately measure lines, curves, diameters, and more. Simply place the primary hash on the start point and roll the device to the desired end point. Every one full rotation is 4", and the hashes are marked at every 1/16" around the edge.

This design uses a pressed-in 608 bearing for smooth operation. The final outer diameter should measure 1.273" (32.33mm) in order for the resulting measurements to be accurate.