Indoor siren via radio 433-80Plus. Bidirectional EN50131 Grade 2 certificate. Compatible with Xgen and Zerowire power plants. Acoustic power 101dB. Tamper box and wall. It works with alkaline batteries (4 x 1.5 V type AA + 1 x 9V) included. Technology via radio 433 MHz -80Plus. Polycarbonate housing. Dimensions: 160 x 110 x 45mm.