This Climaloc black U-shaped door sweep of 36" long can be used with wooden doors or steel doors. Made of vinyl, it contains a 100% natural bug killer ingredient that is safe for children and pets. This door sweep screws on to the bottom edge of your door to seal the gap(1/4" to 3/8") between the bottom of your door and the threshold. It has pre-drilled slotted holes for easy installation. Screws are included.