GENSSI 100W Police Siren 7 Tone PA System Electronic Emergency Sound 150 Max SPL DB Entry Level Siren System Easy to install anywhere with 12V DC Power; No installation guide provided, please consult with car audio installer or mechanic Strictly for Non-Professional Use; Example perfect for volunteer firefighters Hooter/Ambulance/Traffic/Police/Fire Pack of 1; Rated Voltage 12V DC; Output Power 100W Tone 7 tone Impedance 6/8 Ohms SPL 150 DB(1m) Feature with microphone; ISO9001:2000 Approved 100W Rated Horn Size: 120 x 160 x 133mm