Use this Marelux Nylon Zoom Gear for Canon EF 16-35mm f/2.8L II USM with Mount Converter for Sony Cameras with your underwater housing to control zoom on your lens. Specifically made to fit your Canon EF 16-35mm lens when mounted on a Sony camera using a lens converter. Made of strong, yet lightweight nylon, this gear slides onto your lens and fits snugly to avoid slipping.