Variation sets include:

All Unitrack pieces and accessories necessary to make a particular railroad layout, such as a passing siding or a bridge and viaduct loop. Each box comes with suggested layouts that you can build with the different set combinations.

These track sets recreate the effect of Superelevation on rails; what this means is that corners are "banked", with the outer rail being posted higher than the inner rail. In the real world, this is designed for high-speed trains, lessening the stress on the trucks and train through turns and allowing them to take the curves at greater speeds. The overall effect is both subtle yet stunning to watch, and we eagerly anticipate bringing this new N Unitrack to the United States!