An Inon Knob gives you the control you need when adjusting the levels on your Inon Z-330 & D-200 strobes. Perfect for those in temperate waters as it make adjusting the levels a snap 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 Strobes.