The Godox BD-04 Barn Door Kit includes 4 color filters to allow you to have different background colors. They are used to either correct the light balance or create dramatic lighting effects. These are also used to change colors of backgrounds. They are designed to be used with the barn door attachment / lens holder. The Honeycomb designed is to give you ultimate control on the direction of your light. It will emit a beam of light precisely where you aim. These devices alter the shape, intensity, or color of the light output from your flash heads.