Magnetisches Slim Advanced Kit

I bought this protector in the hope of protecting the magnetic slim circular PL or ND filter from sea water or desert sands. Because it is also served as an adapter, the threaded section is thicker than all other slim filters. After stacking together, not only there is a wider gap, but also the magnetic power is weaker, therefore the protect/adp is easy to fall off, and the debris can get in easily.
I wish that you can design a magnetic slim protector only rather than a dual purpose protect/adapter.

Regards, Ingjye Juan