The high-quality stainless steel is processed by hand-drawing to ensure anti-rust and long service life. Product information: The stainless steel safety sliding door lock chain guard plate is made of 304 stainless steel stamped and formed, with a high-quality feel, smooth surface, corrosion resistance, and rust prevention; the anti-theft chain door latch can be used in a variety of door types, and can be placed above or beside the door panel . It has a 5-inch long, 8-inch welded steel chain and all the accessories required for a complete installation. Purpose: The door chain lock of the revolving door, to open the safe viewing channel. This latch with a chain allows you to partially open the door to identify visitors or receive packages. Easy to install: Chain door guards can be used for wooden or metal doors of various door types. It can be placed above or beside the door panel. The latch is very easy to install and strong. The four attached fixing screws do not require additional screws.