A case for loop earplugs to replace the one supplied. Come in two versions a larger model and a slimmer model. You just need to print the case in the size you want and the corresponding lid that screws on.

This is based on the Customizable Container with Knurled Lid by wstein (https://www.thingiverse.com/thing:612709) and also used the loop ear plug case by aubs205 (https://www.printables.com/model/291669-loop-ear-plug-case/files) for the size of the earplugs.