This is the add-a-unit. Add 6 additional rooms to your existing Heath Martin House with the Add-A-Unit Deluxe.  As your colony grows, so can your house. Does not come with roof pieces. Door stops and protective rails are included.  Constructed of Rust-Free Heat Dispensing Aluminum. Smart Hexagonal Design Creating Artistry and Function. Easy to Clean - Floors snap out for easy access. Comes complete with railings and door stops. Assemble with Screwdriver and pliers.