Before installing, hold door viewer with your hand and test the image is satisfactory. We suggest testing day and night and adjust for height.
1. Affix the enclosed drill template/sticker on a desired place where the door viewer is to be installed.
Be sure that the label is stuck on the outside of the door and is kept horizontal in reference to the level line given on the sticker.
2. Drill the large hole all the way through the door. To achieve smooth edges at both side of the cutout, it is best to first drill from outside until the drill tip shows up on the inside. Now you should drill the remainder from inside out.
Caution: The two or 4 small index holes are drilled from the outside and not deeper than 1/4 inch. Do not drill all the way through.
3. Remove the template/sticker from the door.
4. Unscrew the outside piece and insert it into the hole from the outside.
5. With the outside piece held in place and its index pins dropped into the index holes, screw in the main body from the inside.
6. After the outside piece and the body are tightened, fasten the ring nut on the inside to firmly secure the viewer to the door.