The Ferret Nation Add-On Unit (model 183) by MidWest Homes for Pets is compatible with the Ferret Nation (model 181) and Ferret Nation Double Unit (model 182). The Ferret Nation Add-On Unit (model 183) will add more living space to your existing Ferret Nation Cage and offer more room for your small animal to roam. The Ferret Nation Add-On Unit has all the same great features of the Ferret Nation Cage. We included full width double doors that provide maximum accessibility for easy cleaning and feeding. The wide expansive shelf and full width plastic pan floor provide a generous play area and help prevent dangerous falls. Designed with customer convenience in mind we ve included critter-proof dual-locking door latches that provide a secure easy one-handed operation. Shelves include removable plastic trays for easy cleaning and are height adjustable so you can tailor the cage to your pet s needs. The Ferret Nation Add-On Unit also has multiple attaching points for adding hammocks tubes toys and other accessories that are sold separately. Includes appropriately angled ramp that is specifically designed to ensure pet safety. Constructed from sturdy square tube frame and wire the Ferret Nation Add-On Unit has an attractive gray quartz hammertone finish that is sure to blend with any decor. Best of all the Ferret Nation Add-On Unit is easy to assemble and attaches to your existing Ferret Nation Cage - no tools required. Please Note: Ferret Nation Cage (model 181 and 182) is sold separately. You can also accessorize your Ferret Nation with the Ferret Nation Accessory Kits. MidWest Homes for Pets stands behind the quality of our products. Model 183 Includes 1 leak-Proof Pan 1 Shelf 1 Ramps w/ Ramp Cover. Compatible w/ Ferret Nation Models 181 & 182.