The EZ Test™ is a tool designed to determine the condition of your CO₂ lens. It will allow you to evaluate the stress within the lens so that you can quickly determine if you need to change it immediately, or if the lens has more life left in it and just needs a cleaning. In order to maintain the best cutting environment for your laser machine, you need to run a lens that is in optimum condition. The Ophir EZ Test ™ lens polarizer will let you look at the lens and make that determination. The 351280-009 polarizer set includes two cleaning holders of 51 mm diameter, 47 mm clear aperture and 4 mm depth.