NMRA Standards Gauge - On30 Scale
This On30 Scale pocket size gauge is designed by the NMRA (National Model Railroad Association). All of the dimensions (wheels, track, flange ways and points) on your track are able to be checked using this tool. It can help with troubleshooting issues when your train is not running smoothly. This gauge is the same as an "HO" Standards gauge and is currently unavailable with the clearance add on