N gauge
From Conservapedia
For the cell phone usage, see N-Gage
N Gauge is the second smallest scale of model railway available, sometimes also referred to as "N Scale", which is becoming increasingly popular due to people realizing how you can fit so much more model railway (than say with the more popular OO/HO gauge / scale) into such a small amount of space (as little as 5 ft x 2 ft for a double track layout).
There are a few variations of it, all running on 9mm (0.35433 inch) gauge track, including:
European / American N gauge (1:160 ratio, 1.9mm = 1 ft)
European Finescale N gauge (as above)
Japanese N gauge (1:150 ratio, 2.03mm = 1 ft)
British N gauge (1:148 ratio, 2 1/16mm = 1 ft)
