N-gauge track and components are also used with larger scales, in particular H0e (or "HOe") and 00-9 scale for modelling narrow gauge railways. N-scale models on Z-scale track are used to model metre gauge (Nn3). A small amount of 2-foot (Nn2) industrial narrow-gauge modelling in N scale using custom track is done, but suppliers of parts are few. Nn18 layouts use T-scale track and mechanisms to represent minimum gauge railways. N-scale trains and structures are often used on HO or larger layouts to create forced perspective, or the illusion that an object is further away than it actually is.