I rebuilt my mailbox rack and replaced the mailboxes and did not want to pay for the small index card sleeves used to label mailboxes & names of residents. 

I designed this 2"x3" label holder with one slot for a clear piece of plastic, and one slot for a piece of paper or index card for names. cutout on the back to ease pulling and changing the label.

Printed in PLA, real-world testing TBD. I plan to attach using command strips.