Atlas N Over ‘N Under Pier Set (25pcs) – AT-2541 Two each of 12 graduated concrete piers plus #2542 Straight Pier Girder. Pier heights range from 9/64″ through 1-111/16″ by 9/64″ increments. Grade with piers spaced at 5″ intervals is 2.8%. This item is intended for modelling use and is not a toy. Actual product may vary slightly from the pictures shown.