What’s the tool you bought and never use but saves your butt when you do need it?

I used to own semi trucks, so I bought a complete set of Snap On 3/4" drive sockets from 3/4" to 2-5/8". I don't have a need for them much anymore, but when you need one there handy to still have.

Tom

I have a set of craftsman nut and bolt extractors made to remove rounded off hardware. They have come in very handy removing exhaust bolts.