7 mm scale, also known as British O scale is a model railway scale of 1:43.5 (or 7 mm to 1 ft; hence its name).
[1] ScaleSeven (S7) standard however specifies 33 mm gauge, which is closer to scale.
[1] For narrow gauge modelling, 16.5 mm gauge
This model rail-related article is a stub.
You can help Wikipedia by expanding it.