The Entry Alarm with RF Remote Control is an effective door or window alarm that can be activated from the remote control. The three different radio frequencies allow you to arm and disarm multiple units in your house with one click of the remote. Alternatively you can tune the channel of the remote to operate different sets of units within your house. You can easily customize your wireless alarm. Just install the main unit and the magnetic bar on the frame of the door or window, using the powerful adhesive tape. When the door or window is opened the alarm will emit an intense 110dB siren. This is a very economical way to keep someone out of someplace you dont want them to be, or alert you of their presence. Main unit uses 3AA batteries (not included). Remote uses 3 LR44 batteries (included).