CANON DROP-IN CLEAR FILTER AFor Drop In Filter Mount Adapt. EF EOS R Clear, Protective Filter For Use When No Filter Effect Desired ###split### 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. I t is primarily used when the Drop In Filter Mount Adapter is in place, but no filter effects