Panel to cover up cat flap hole

[jobnockey]

We're soon to move house and want to take expensive sureflap cat flap but what do I do about the hole left in the door? I'm sure I've seen a panel that slots over somewhere but can't seem to find it anymore. Does such a thing exist?

If it’s a upvc door you can buy plain panels and fit them easily. The panels pop out really easily.

Couldn't you just put a cheap, regular cat flap in its place?