HIgh QualityMade of high quality copper material with plating process, corrosion resistant, more solid and durable.Adopts high technology optical glass lenses to ensure clearer view. 220 DegreeA nice 220-degree visual angle provides the security of identifying visitors from behind a locked door. The lens will secure your home against burglary and home invasion. Back CoverThe viewer has a a lid of 1.5mm thickness, cover the lenses by manually rotating the lid to well protect your privacy., it can stop others peep across your door to keep your house safety. Simple InstallationSuitable for 36mm-60mm thick doors, tube diameter about 22mmsimply drill a suitably positioned 22mm to 25mm diameter hole, insert the viewer into the hole then screw the two sides together and tighten by hand, replace your door viewer in 5 minutes with no tools required. Widely UseDelicate processing, suitable for doors, wooden doors, iron doors, bedroom doors. Material: Copper + Optical Glass How to measure: please take the old door viewer first and measure the hole size. If there is no door viewer, please measure the thickness of the door. How to install: 1. Leave the door viewer in two parts. 2. Insert the lenses from the outside of the door. 3. Insert the base from the inside. 4. Tighten the slot by hand or with a screwdriver. Size: 1: opening 14mm: suitable for door diameter 14mm, suitable for door thickness 35-55mm, tail cap 22mm,2: opening 16mm: suitable for door diameter 16mm, suitable for door thickness 35-60mm, tail cap 25mm Color: 1:Silver, 2:Red bronze, 3:Bronze, 4:Sand gold, 5:Bright gold Material: Steel Package includes: 1pc*Anti-theft door cat eye door mirror