Chrome Super Loud Grille Mount Single Electric Blast Tone Horn Kit For 12V for Mazda 3 This listing is for a single (1 piece) horn for 12V systems. These horns use a standard blade connector on the back. Rated at 118dB, these horns are nearly 7X LOUDER than a stock horn (@ 96dB) Each horn has a diameter of 123mm (4.8"). Horn has depth of 70mm (2.7").