Also if you look most of the really small ones are for transport and when sick.
Something like that would have been good when Ringo was at his worst or after a spay or neuter.
From site:
[align=left]This is basically for use as a temporary holding pen. The pen will fit into most hatchback or estate cars either folded or erected and is ideal for transporting your cats on long journeys.[/align]
[align=left]The 'FLATLET' is also suitable for use as a hospital pen, providing just enough room for a bed, litter tray and feeding/drinking bowls. The size of the pen will discourage an injured or sick animal from climbing or from any strenuous movement whilst it is recovering. Also, the full width doorway allows for careful support of an injured or anaesthetized animal when being placed in the pen.[/align]
[align=left]Apart from the quick folding 'Flatlet', this is the smallest of our pens. It is still large enough for a litter tray, feeding bowls and a bed. It can be used as a short term holding pen or as your pets own place to stay and sleep. If required, the door can be removed or replaced in a few seconds. [/align]
[align=left][/align]