Tracksetta: N Gauge: Track Laying Tool 18" 457mm Radius. Blue.
The Tracksetta system allows for simple track laying when using flexible rail. Simply insert the metal Tracksetta gauge in between the rails and the line will automatically form to the correct radius. Now tack through the sleepers with track pins to secure the track in place, and slide the template along the line. Each radius follows prototypical design.
Image included for your information.