Ferum 902PBR Polished Brass US3 Keystone Door Viewer, specially designed with a wide angle precision lens, a 180 degree field of vision, and it fits doors from 1/8" to 2-1/8". This door viewer is easy to install, all it requires is a 1-3/4" inch diameter hole to fit the lens through the door. The face-plate measures 4" tall x 3-3/8" wide, and it has a window frame slot for a family name, room number, or office title.

Directions:

Step One: Measure eye level of shortest adult in household.

Step Two: Locate center of door. Unit usually goes in center of door,m unless center of door contains glass panel, in which case unit would then go on side of door near lock.

Step Three: A. if door is MORE than 1-1/8" in thickness, use 1-3/4" template. B. If door is LESS than 1-1/8" in thickness, use 1-3/8" template. This thickness pertains to CENTER of door, not sise, which is usually thicker.

Step Four: Drill Hole.

Step Five: In the case of three A, insert viewer into hole and thread large flanged ring on (see illustration). Tighten ring, making sure that any one of the four locating holes is in 12 o'clock position. Screw cover on.