Sea&Sea Zoom Gear for Canon EF 17-40mm f/4L USM Lens @light Some situations underwater require as

Some situations underwater require as much light as you can get

A low-volume dome port for use with interchangeable super wide angle and fisheye lenses

[Construction] Corrosion-resistant aluminum alloy (alumite coating)

INON Grease

this Fiber Optic Converter features heightened sensitivity for use with SEA&SEA or Nauticam housings with internal electrical-to-optical flash triggering devices

Sea&Sea Zoom Gear for Canon EF 17-40mm f/4L USM Lens @light Some situations underwater require asSea&Sea zoom gear enables zooming for the Canon EF 17 40mm f 4L USM lens via the housing's focus zoom knob when used with Sea&Sea MDX RDX housings.