This is a necessary item if you need to take the VND filter or polarizer filter out of your - Canon Drop-In Filter Mount Adapter EF-EOS R - this takes the place of an effect filter and offers no effects to the image but allows you to use the same mount adapter by only needing to swap the drop-in filters instead of the entire mount. The adapter can be found here - https://www.ebay.com/itm/266636787137

Key Features

Designed for use with the Canon Drop-In Filter Mount Adapter EF-EOS R, this Drop-In Clear Filter A is a simple clear protective filter used to guard the interior of the camera body and rear element of the lens when the lens adapter is in use. It is primarily used when the Drop-In Filter Mount Adapter is in place, but no filter effects are desired.