The center core of the flat wire coax is "copper-clad steel". It was chosen for its strength and resistance to metal fatigue. The film is made of ALPET (ALuminum/PET plastic, same material as milk jugs) to resist damage upon closing the door or window. 24k gold plated female connectors are supplied with screws to attach the connectors securely to the wall/window frame.Close the window and screen securely to keep out weather while keeping your home secure without damaging the coax! SO-239 connectors