Extension hook for key holder

I quite like jil8's key holder, but the hooks are too big to accept standard key rings!

I opted to fix it additively rather than subtractively. Here's my solution.

You can print one for each hook you want to upgrade with the ability to hold smaller items. Simple print, flat bottom, no overhangs. Fits tight around existing hooks (no post-processing for me, but a little sanding will help if it comes out too tight) and holds firmly.

Note this is just the extension part - you also need the key holder itself, linked in the "Remixed from" section.