Mamiya ZD digital body IR CUT FILTER or LOW PASS FILTER protective empty cartridge, new/never used in original case.  This protective empty cartridge came with the purchase of the ZD body or IR cut/low pass filters as STORAGE for the filters.  When not using the filters then you can store them in this cartridge that has the slide up/down mechanism and a hook to hold the filters in place, and also has functions of release and lock transporting the filters safely into the body.  Although the cartridge indicates "IR CUT FILTER", but it can also be used for the low pass filters as both types are exactly the same except for the white lettering outside (one can just tape over the IR CUT FILTER wording with your own writing of LOW PASS FILTER instead).

*overseas buyers are responsible for duties/taxes (if any)*