Lets say you live in a place without the best water infrastructure and are constantly being bothered by the water pressure issues. Ideally, you'd be able to fix them, but sometimes that isn't an option. 

This “tool” helps by fitting into the gap created by you pulling on a shower head pin and not allowing it to fall down, ensuring the shower head stays on.

You can adjust the thickness or the dimensions as you'd like, but I feel that most pins are the same.

Used this persons' arc module: https://www.thingiverse.com/thing:1092611