This gauge supports precise routing of the jig saw by displaying the cutting line for DeWalt DCS 331 and 335.
Just slide the gauge beside a router (e.g. a 3030 aluminium extrusion) and it will show we're the saw will do it's job. In case you have a target cutting line: just clip two of the fixed gauges to a 3030 extrusion profile, fine-position the router by placing the gauge's mark at the beginning and end of the cutting line, clamp it and use it for guiding the jig saw with ease.
The router was calibrated with a Bosch T101B blade. Other blades can be smaller/thicker.
The author hasn't provided the model origin yet.