The door-viewer that is easy to install, well-made, and it provides a clear wide-angle view. The interior viewing hole is a good size to look out of, and the fancy little rotating cover offers peace of mind that no one can in.Features-Material: Zinc alloy.-Size: About 7.00X5.50X5.50cm/2.75X2.16X2.16in.- Battery: 2 x AAA batteries(Not included).- After installing it, you could see a lot of the area. It offers the security for you and your family.- It is a modern security door viewer and peep hole for doors.- Fine workmanship and creative appearance ensure its popularity and practicality.- Perfect peephole for home, office, hotel and front door, etc.- Where you need to see, monitor, and peeking who is outside your door when the doorbell rings before opening, providing you extra privacy and safety.-Instructions for use:1. Open to the left or right.2. Use your finger to lightly press the battery cell position, pull out the inner core after the inner core is separated, and press in 2 AAA batteries on the inner core.3. Put the inner core back in its original position, and press it in with your hand to make it jam.Note: This inner core is a cycle . Click to release, and to jam.Package list: 1 Viewer