The Time Travel Aid collar tac pin is designed by Mark Eliot Schwabe. Each pin is cast, and then he adds additional details by hand. These additional details are unique, so pins are a little different one from another. More of his work can be seen on his etsy site SteamSmithWorks.

"Trips through alternate timelines are often bumpy, and sometimes eventful in an unfortunate way.
After considerable study and diligent efforts at development, I have created a truly remarkable item that addresses the problems generally associated with temporal travel.
It appears to be a common lapel pin, but it is so much more. It is an Aid to time travel. I personally guarantee that wearing this item will make your next journey through time smoother and more pleasant than your last such travel.

your humble servant, SteamSmith"