Use this Sea & Sea Zoom Gear to control manual zooming with your Sony FE 12-24mm F4 G E-mount lens in a compatible port, which will be mounted onto the MDX underwater housing for the a6000, a6300, or a7 II camera. For full compatibility information, see the MDX System Chart.. Manual focus cannot be used when this zoom gear is in place. The gear mounts onto the zoom ring of the lens and is controlled via the focus/zoom dial/knob on the housing. It is constructed from a corrosion-resistant aluminum alloy.