7 SIREN SOUNDS: The car siren speaker can offer 7 loud and clear sounds, including siren, fire alarm, ambulance, traffic, police, etc. Please do not use the siren in emergency. PA SYSTEM: The car siren speaker is built-in PA system, you can talk to others via the microphone (included) INSTRUCTIONS: Power siren with 12V or car battery. The power voltage must match the working voltage and please make sure the cable connection is correct, otherwise it will not work properly. EASY INSTALLATION: With mounting bracket, installation is simple. The sound car siren is handy but loud and clear for its size. Please do not be used as a replacement for professional equipment siren. PREMIUM QUALITY: The sound car siren is constructed from premium quality materials to ensure maximum strength and durability for long lasting usage