Velocity DUAL Super Tone LOUD Blast 139Db Universal Euro BLUE ROUND HORNS (Quantity 2) High / Low Tone Twin Horn Kit Pair Compact Extremely LOUD Audi GT R8 GT TT TTS V8 50 72 75 80 90 S2 RS2 Cabriolet Universal Fitment / 30 AMP Relay and 2 Mounting Brackets plus Instructional Installation Diagram Included Super Loud - Sound Output: 139DB - 400-335 HZ / 12V Power Source - No External Air Supply Needed Made of Steel and Powder coated in BLUE 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.