Expand your existing train layout with the Lionel HO Gauge Curved FasTrack Terminal If you can dream it, you can build it! Trains and scenery are often the stars of any layout, but any seasoned model railroader will tell you that a good track layout is the key to years of trouble-free fun. Lionel HO Gauge are 1:87 in scale, are half the size of the traditional O Gauge and have become the most popular model railroad scale in the world today. These are small enough to build a gratifying layout in an efficient space and are large enough to illustrate all the great details. HO Gauge products operate on a 2-Rail HO FasTrack System that has a fantastic exemplary look and features a quick easy snap-together connection.