Canon 52SFHWII Screw Filter Holder

The technical details behind this filter holder
Easily incorporate gelatine filters into your super-telephoto lenses with the Canon 52GFHWII Drop-in Gelatin Filter Holder. This filter holder is designed for super-telephoto lenses, such as the 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.
Key Features

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
Top three reasons we think you will love this filter holder

Perfect fit
Works great
Easy to use