Install the Oplink Door and Window Sensor throughout your home to bolster your AlarmShield or TripleShield security system. This sensor is battery powered and mounts to all types of surfaces using double-sided tape. Add-on sensor for AlarmShield and TripleShield security systems Immediate notification sent when contact is broken Install on just about anything that opens and closes No limit to the number of contact sensors you can add to either system Battery powered