An Inon Z-330 & D-200 Light/Circuit Knob gives you the control you need when adjusting your Inon strobes. Perfect for those in temperate waters as it makes setting the small knob with gloved hands. The Light/Circuit Knob presses onto your existing knob and is secured using a small set screw. The Light/Circuit Knob is constructed of durable impact resistant Red plastic. This knob is for Inon Z-330 & D-200 .