Even if there is an power outage, your doorbell will still work. The DH992 mechanical doorbell also includes a peep hole viewer for added security. You can check the visitors before opening the door.
The DH992 is easy to install and use!
For new or replacement applications
Mechanical operation works without electricity
Includes peep hole viewer for added security when opening the door
Chime designed to mount on doors and walls from 3/4" to 4-3/4" thick
Viewer designed to mount on doors from 1-1/4" to 2" thick
Easy to install, includes chime, name plate and viewer