Automatic door sweeps are the perfect door sweeps if your door is crossing carpets or rugs. Automatic door sweeps will rise when the door is open to clear carpets and rugs, and seal the gap between the door and threshold when the door is closed. To install, the sweep is attached to the side of the door facing the door jamb using the provided screws, and a "roller" (plug) is inserted into the door jamb. When the door sweep presses against the roller, the roller presses the vinyl flange against the threshold. The sweeps are suitable for sealing gaps up to 1/2" between the threshold and door bottom. These Macklanburg-Duncan (MD) sweeps come in white or dark brown, and are 36" (91.4 cm) in length.