Heat-Set Insert Tip case for 3DZWMAN (brand name) insert tips. Uses tight fitting print-in-place hinge to keep lid closed. Dual-color option to add labels changes colors just six times.

The case was designed for a insert tip set sold by 3DZWMAN on Amazon.

https://www.amazon.com/3DZWMAN-Soldering-Heat-Set-Connecting-Accessories/dp/B0C8BGWTYP?ref_=ast_sto_dp

It includes tips for M8, M6, M5, M4, M3, M2.5, M2 and a soldering tip.

Other sets or brands may or may not fit into this case.