FREMO
The Friendship of European railway modellers (, FREMO) is a modular rail transport modelling standard. Individual track and scenery modules are built to a common standard and are joined together to make larger model railway layouts. The FREMO standards were created following a meeting in Europe in 1981. Modules are wide, with variable length and viewable from both sides. Each module comes with adjustable legs, to create a uniform top-of-rail height of above floor level. Modules are physically joined together using three holes and hand-tightened M8 bolts with washers and wingnuts. The electrical inter-connection uses two  Banana connectors per track bus, over which Digital Command Control (DCC) signalling running at 14 volts is used for train control. Track uses Code 83 rails ( high), with a minimum curve radius of ; representing at 1:87) and fixed track centre-line spacing of ; representing separation at 1:87 scale). Some general aspects, such as rigid construction of modules, are derived from the NEM 900 standards published by MOROP. In 1995, the North American Free-mo standards were based on those of FREMO, with a number of changes made. N-scale variant. In 2004, the traditional Free-mo standard was adapted for  N scale (1:160). It uses Code 55 rail at a nominal height of . Curves should not have a radius of less than on the main line and use turnouts sized  6 or larger.