If you have a GATS jar tester, you need at least one these as a spare. Buy one with your next GATS jar tester.

Great item to replace an old plastic pin on an old GATS jar. Just popped the old plastic pin assembly out and popped this one in. May take a little effort to get the pin assemby out as there is a raised nub on the tube part that holds in place. Altogether this item does what it is designed to do.