NEW K9 BSD Dopamine box comes two sizes LARGE (12in x 12in) for Adult and Larger dogs and SMALL( 8in x 8in) for puppies and smaller dogs. The LARGE box will fit a Large Klack Klack in it and SMALL box will fit a small Klack Klack. They are constructed from High-density polyethylene (HDPE), known for its high strength, chemical resistance, moisture barrier, and durability.