The Muddy Outdoors Universal Box Blind Curtain Kit is compatible with PENTHOUSE, BULL, and GUNNER Box Blinds! The Universal Box Blind Curtain Kit features the black side out to keep you concealed. The Velcro strips hold curtain kit to Window; Peep Hole included. Curtain kit includes enough window covers for the entire box blind. The curtains are constructed out of a quiet, blacked out fabric.