Canon Drop-In Variable ND Filter

Canon Drop-In Variable ND Filter(3446C001) A neutral density filter for controlling exposure in movies and prolonging shutter speeds for a variety of creative movement effects in photographs.

Canon 52mm PL-C Drop-In Circular Polarising Filter (WII)

Canon 4774B001 (47-74-B0-01, 47/74/B0/01, 47 74 B0 01 47 74-B0/01) 52mm PL-C Drop-In Circular Polarising Filter (WII) Benefits Drops into EF 300mm f/2.8L IS II USM, EF 400mm f/4 DO IS II USM, EF 400mm f/2.8L IS II USM, EF 500mm f/4L IS II USM and EF 600mm f/4L IS II USM lenses Built-in gearing rotates the filter when it's inside the lens, to vary the intensity of its effect. Reduces the appearance of reflections in non-metallic surfaces Makes colours appear more saturated