Brrrrrrrrrrrrrrrrrrrrrrrrm
Here we have a blank card & envelope
It's around 14cm square
There is no message inside or out so, handily, can be used for the occasion of your choice!
Free P&P
Standard post is 2nd class, but you can upgrade to 1st if you are in a hurry. I usually post on the same day, but if not it will be next day latest