This is a simple sign for a Gibraltar Patriot Mailbox. The size is the exact right size for the opening in the front. It is intended to be printed on a Bambu with AMS.
There are some instructions to get this to work:
I used 3M double sided tape to tape the signs to the box, and it works surprisingly well. I posted a picture of the exact roll I used.
Some links:
The mailbox: https://www.amazon.com/gp/product/B01KJEFJ4I
If Amazon is out, Walmart sells them too.
An alternate mailbox flag for this mailbox: https://www.printables.com/model/749775-mailbox-flag-for-gibraltar
(not my design, and I do not know if it's any good, but I just printed it myself to try)
The pictures of my mailbox show it all destroyed by the snow plow, an unfortunate reality of where I live. The signage came off easily. I cleaned off the old tape, washed the signs with water and soap, and installed them on the new mailbox (also in my pictures).