This case is designed to securely hold a pair of loop earplugs as well as four "mute" accessories.  It's primary closure is via two pairs of 8x2mm circular magnets, but I don't trust them on their own so I designed in a tab detent as well.  To open, pull the lid up toward the keyring, then rotate.  The screw that holds the case together is also a pivot.

Printed at 0.2mm layer heights in Prusament Ultramarine PETG on my Core One+ using more or less the default profile.  I included supports on the bed for a little reassurance.