RC 8 Door bell / Magnetic Contact for closed doors with two buttons/contacts Picture will show one contact , purchase will come with two contacts
Will operate by means of a coin cell battery when the door opens .
Battery life of about 3 to 6 months
Double sided sticky tape will insure a very simple and easy installation
There is a setting for a continuous tone as long as the door is left open .'
Electrically powered up to 1000 feet from the front door
Unlimited transmitters and receivers may be used.