The Kase K9 Filter Holder Slim Kit for 100x100mm and 100x150mm rectangular filter was developed as a filter holder solution for conventional filters with a thickness of 2 mm as well as for our new K100 SLIM filters (1.1mm thickness).As a special feature of the filter holder has a newly developed 90mm circular polarization filter, which is attached using magnets and must not be screwed into the adapter ring. So the quick attachment or removal of the pole filter is possible in the application.