Plastic Wing Clips will not rust and are corrosion resistant. The clips are attached to the window frame with a Pan Head Phillips Sheet Metal Screw for wood, or a Pan Head Phillips Machine Screw for metal frames. These Clips will accommodate both screens and storm window panels. Available in Gray (1/16", 3/16", 5/16",and 3/8"), Black (5/16", 3/8", 7/16") and White (1/16", 5/16", 3/8", and 7/16") (Screws not included)