Genuine andersen product Andersen auxiliary security lock with screws - satin nickel finish works with 200 series narroline, 200 series perma-shield and 400 series frenchwood gliding patio doors manufactured from 1978 to present. This security lockmonly referred to as a "foot" lock and is a installed to the side of the operating panel and when depressed a pin is engaged into the door track allowing for additional security. This "foot" lock can easily be engage and and released with your foot.