Accepts GFCI, duplex, switch and up to 1-3/8 in round devices. Nonconductive, noncorrosive and impact resistant. Won't rust or fade. Scratch-resistant. For use in wet/damp locations. Keyhole mounts, loosen the existing device screws and slide the cover over. Comes with adapter plates and pre-adhered gaskets. Wasp guard included to keep out unwanted pests. Lockable for security. UL listed.