HO NMRA standard These modules have a double track toward the front of the module with a back drop. Most setups form a loop with an open pit in the center for operators. The module above is one of four corners that form a loop for continuous running. This module is one of two modules that have an optional siding for additional operational purposes. In the background is one of the Free-mo modules connected to the NMRA loop.     HO Free-mo These modules have a single track centered on a two foot wide end plate. Modules can be of any length, however, most are two feet wide for ease of handling and transportation. The module above was constructed from tracks salvaged from a layout being dismantled.   (c) 2012 San Luis Obispo Model Railroad Association - All Rights Reserved