DUAL Super Tone LOUD Blast 139Db Universal Euro RED ROUND HORNS (Quantity 2) High Tone / Low Tone Twin Horn Kit with Bracket Pair Compact &ndash; Extremely LOUD for Car Bike Motorcycle Truck for Porsche 356 911 912 930 914 924 928 944 959 968 Boxter Carrera GT Cayenne Cayman Panamera Universal Fitment / Relay and 2 Mounting Brackets plus Instructional Installation Diagram Included Super Loud - Sound Output: 139DB - 530-680 HZ / 12V Power Source - No External Air Supply Needed Made of Steel and Powder coated in Red Color for a Long Lasting Finish Mounting Type: Single Screw - Terminal Contacts: Blade Type - Includes 2 Universal Mounting Brackets Diameter = 4.89 / 124mm (without mounting bracket), 5.31 / 135mm (with mounting brackets). Depth (Thickness) = 2.65 / 67mm. They can easily be tucked behind Most Vehicles Grills.