Our UnitPak® Storage Sustem boxes are all 11-1/4 inches square and 1-1/2 inch deep. We use high-grade electronics foam that is specially selected for longevity and is gentle on your trains. It will not interact with apint or printing either. Our Twin Tub coal gondolas and RoadRailer trailers come in 10-packs which use the UnitPak® box

TrailerPak® Freight Car Storage Box #990710

We use high quality electronics grade, non-degradable foam in our storage boxes. The inside is about 11 inches square. The DeLuxe UnitPak® boxes fit in standard office file boxes or milk crates for easy toting or storage. They even have spaces on the outside to list their contents.