That squarish key is for the mailbox of our government housing.. they a pain to duplicate accurately.. I usually have to bring it back a few times before it works.. a lot of shops are unwilling to duplicate such keys and when they do, they charge very expensive here in Singapore.. that square thingy is a stamped ID fob made of an aluminium bar or copper from Etsy.. It's listed as bar dog tags by themadstampers.. Of course being edcers, how can we NOT have COPPER!! So I have both lol.. Sent from my Mobile Command Centre on Tapatalk.