H0m gauge

The H0m gauge is designed for the reproduction of narrow gauge railways with a prototype gauge of 850 to 1250 mm in H0 scale. The letter m stands for metre prototype gauge with a track width of 1000 mm. It runs on TT scale tracks. Modern H0m trains run on realistic-looking two-rail track, which is powered by direct current (varying the voltage applied to the rails to change the speed, and polarity to change direction), or by Digital Command Control (sending commands to a decoder in each locomotive). It is a popular scale in Europe, particularly for trains of Swiss outline.

Ready to run models are widely available from companies like Bemo and D+R Modellbahn, a number of companies including, Lemaco and Ferro-suisse, also produced more detailed handmade brass models.

H0m track is also used in Australia to model the narrow-gauge lines in Queensland, South Australia, Tasmania and Western Australia where trains run on 3'6" track. Likewise it has a following in South Africa, Japan and to a small extent Taiwan and New Zealand which also use 3'6" tracks. See HOn3½ gauge.

Related scales
In the same scale standard-gauge trains are modelled on gauge track, known as H0. Narrow-gauge trains are usually modelled on gauge track which is known as H0e and industrial minimum-gauge lines are modelled on  gauge track known as H0f gauge. HOn3 is used to model gauge railroads in the United States and uses a track gauge of.