Trains are operated using direct current or Digital Command Control over realistic-looking two-rail track.
Railways that use the 3 ft 6 in (1,067 mm) gauge can be found in New Zealand, South Africa, Indonesia, Australia, Taiwan, Japan and others.
The main focus for Australian narrow gauge modelling has been the large Queensland railway system.
More recent releases have included Tasmanian and Western Australian prototypes.
Most Japanese and Taiwanese HO scale models are made to run on 16.5mm gauge track and are made to 1:80 scale (Tomix, Kato and Tenshodo for Japan being the main brands and Haskell for Taiwan) but some small volume HOn3.5 kits and brass models are made for Japan with Imon being a major supplier.