These are HO scale 1/87 3D printable hopper cars used for wet rock phosphate and sand service by Seaboard Air Line SAL, Atlantic Coast Line ACL, Family Lines, Seaboard system, and CSX. Used from the early 1940s into the late 1990s. A later version with a seam on the sides is included. Also, variations of the file with and without the mesh at the ends of the cars are included. U-11, US-11, H-6, H-6-A.