The Atlas Over-N-Under 47-Piece Pier Set makes it easy to elevate your HO Scale right-of-way in minutes with this set. The 47-piece set includes 46 graduated piers which snap in place under your track to lift the rails up and over. Additional piers and Pier Girder sections are also available. A pier girder and snap-in shims are also included. The Pier Set, Piers and Pier Girders work with Atlas and most other conventional HO Scale Code 83 or 100 sectional track.