Canon 52mm Protector Filter

The Canon Filter Holder (52mm) is a circular polarising filter specifically designed for Canon super-telephoto lenses. It can be used with the EF 800mm f/5.6L IS USM and EF 200mm f/2L IS USM lenses, as well as other compatible lenses. The filter has built-in gearing that allows it to rotate within the lens, giving the photographer control over the intensity of its effect.
One of the main benefits of this filter is its ability to reduce reflections in non-metallic surfaces. This can greatly improve the quality of photos taken in bright or reflective environments. The Canon Circular Polarising Filter Holder (52mm) is a useful tool for photographers looking to enhance their images and achieve better results.
 

Allows 52mm diameter filters to be used in Canon super-telephoto lenses that take drop-in filters.
Drops into EF 800mm f/5.6L IS USM and EF 200mm f/2L IS USM lenses
Allows the use of screw-in 52mm filters