I needed a small double hook to attach a self-created key fob to my kar keys for easier identification when in service etc. Good I came across the original design (https://www.thingiverse.com/thing:1990212) which has just the right size and is really strong - I combined two of these hooks, editing away the curtain ring which was noc longer needed (for my purposes). Result - a nice small lightweight but strong keyring carabine hook.