Polon Alfa SAW-6001 Addressable Siren has Electronic circuits with piezoelectric sounder are fitted into red housing made with flame retardant material. Inside the housing, there is a place to put and connect 9 V battery. The sounder is installed in G-40S base which is made with the same material and which is a kit with the sounder. There is a screw less connector inside the base for connection of wires. There are six connectors: two pairs marked as €œ+€ and €œ-€œ for connection of detection loop (input and output) and two for optional external power supply.