Sickspeed Blue Super Loud Single Electric Blast Tone Horn for Car/Truck/SUV 12V P1 for Mazda MX-5 Miata Let them know you're coming with this 118dB horn. Uses a standard blade connector on the back. Horn has a diameter of 123mm (4.8"). Horn has a depth of 70mm (2.7"). For use with 12V systems.