Spark plug keychain

A keychain, modelled from a real life spark plug. I designed the tip of the plug (the spark) as a fidget button.

It only needs a compression spring. The exact size and spring force does not really matter as long as it fits inside the parts. (I used a 0.5x7.0x17 spring)

The fitting of the parts are not too tight, so a drop of super glue might be needed.