The selected item is a vintage Disabled American Veterans (DAV) miniature license plate keychain tag from the 1950s.

About DAV KeychainsPurpose: The Disabled American Veterans organization mailed these mini license plate tags as a fundraising tool.

Return Service: Each tag featured a unique number matching a vehicle's license plate and the DAV headquarters address.

Lost Keys: If someone lost their keys, a finder could drop them into any postal mailbox, and the post office would return them to the owner via the DAV. Along with this is a pocket knife that is attached !