Product details:

High quality, maintenance free, no wiring, no batteries, one way viewing mirror. Designed to fit wood and steel doors up to 1-3/4" thick. Requires to drill 5 holes through the door. (See the paper template in the pictures above). Mounting and fastening hardware includes only screws for wood doors. High quality, maintenance free, no wiring, no batteries. Requires to drill 5 holes through the door. 1st hole is 1-1/2" Diameter (1.50 inches - 3.81 cm), and the other 4 holes are 3/8" Diameter (.375 inch - .95 cm). (see the installation positioning paper template in the pictures above, for the size and location of the 5 holes. To drill the holes, the actual paper template goes on the door, and it shows exactly where to drill the holes). Before purchasing please make sure that any existing holes in the door won't interfere with the holes required to install this door chime. Designed to fit wood and steel doors up to 1-3/4" thick. Has a one way viewing mirror. (It does NOT have a wide angle view, It's simply just a piece of tinted glass. The view looking out is just like looking through a tinted window. It's called a 'One Way Viewing Mirror,” because looking at it from the outside, the tinted glass is a mirror). Outside metal faceplate measures 6-5/8"H X 3"W. The inside white plastic cover has a spring activated sliding viewer. Has paper tags to write apartment identification number and name. Mounting and fastening hardware includes only screws for wood doors. Easy to follow instructions. Choose from 2 colors, gold powder coated metal or silver powder coated metal.