Official Standards Gauges for Sn3 by NASG

NASG (click for web site)

official standards

Sn3

metal

The NASG carries the official NMRA Sn3 Standards Gauge for S-scale 3-foot narrow-gauge track. This gauge can check the track gauge (including turnouts), the equipment's wheel gauge, and the required clearance for items surrounding the track. These three can be combined, because there was only one era during which narrow-gauge was active.