These are included with the new LED 600 model so no need to order them unless you have one of the original LED 600 models. The LED 600 Filter panel set includes 4 1/6" (2mm) acrylic panels (1/4 minus green, 1/2 minus green, full CTO and diffusion) all in a nylon carrying pouch. Just slides right in behind the barndoors as needed. Or, if not using the barndoors, put them in the accessory slide where the barndoors go and use the LED 600's spring loaded accessory lock to hold them in place.