The Wooden Camera Bottom Flag for UMB-1 Universal Matte Box attaches to the bottom edge of any Wooden Camera Universal Matte Box. This anodized aluminum flag blocks stray light from under the lens and prevents it from flaring your lens or filters. This unit consists of the flag and hinge assembly that you attach to your matte box. Once the hinge is attached, you secure your flag to your matte box by slipping it onto the hinge assembly and tightening it in place with the two small thumb knobs. The flag is hinged, allowing you to fold it in half for storage.