The Relay-Interface is needed, if the line doesn’t allow to connect glass break detectors. This could happen because of several reasons: At series-technology, digital supervision or if the line-voltage is below 3 V. As a connecting link between a glass break detector and the panel, the Relay-Interface can be connected at or in each loop because of it’s floating relay-contact. The electronic is placed in a plastic case. It allows the lead-in of wire on three sides. The housing-cover is monitored against unauthorized opening by a tamper-switch. Secondary Packaging: 25 Units