Remix of Andrew's case modified by inserting nr. 2 6x2 mm magnets, two small protrusions to facilitate opening, slightly retouched the hinge.

Perfect fit 3M EarPlugs.

Step file in Raw Model Files section.

BOM:

Nr: 2 Round Magnet 6x2mm Neodymium

like this:

https://www.aliexpress.com/item/1005001832498712.html?spm=a2g0o.productlist.main.5.50711dbeFUM8YB&algo_pvid=0832e69a-c31e-4550-9c21-8a53a8acc4de&algo_exp_id=0832e69a-c31e-4550-9c21-8a53a8acc4de-2&pdp_npi=4%40dis%21EUR%215.12%210.46%21%21%215.44%210.49%21%4021038e7717106862057811277e6d13%2112000017789825032%21sea%21IT%210%21AB&curPageLogUid=xxWdceSiETaw&utparam-url=scene%3Asearch%7Cquery_from%3A