Black Flexible Aluminum Alloy Camera Matte Box Kit for 15mm Rod Support Product Description Matte box install on the end of lens to block sunlight during shooting, to stop from the glare. Usually it may be the same function as a lens hood mounted in front of the lens. Three removable french flags design for flexibility and easily taking, also provide excellent effect of shading. Another purpose of a matte box is to hold glass or plastic filters in place in front of the lens.