A Vehicle Specific item is specifically designed for the exact measurements of your vehicle. No alterations are required.

A universal fit item is designed to fit and work with almost any vehicle. It will work with your vehicle, but may require some modifications to fit exactly.
RV > Horns : MARINE HORNS
 
WOLO ELECTRIC STAINLESS STEEL DUAL TRUMPET 116dB HORN
$104.99
This double trumpet stainless steel beauty delivers a dominating blast that gets slow pokes out of the way! Highly polished 304 non-magnetic stainless steel trumpets look sensational, won't rust and are designed to withstand demanding exterior conditions. 12-volt hookup eliminates the need for hoses or compressors; includes adjustable stainless steel trumpet support and mounting hardware.

WOLO PERSUADER™ ELECTRIC STAINLESS STEEL SINGLE TRUMPET HORNS
$62.99
Stainless steel horns look sensational and deliver a commanding blast! Designed for demanding exterior applications, the highly polished 304 non-magnetic grade stainless steel won't rust. 12-volt hookup eliminates the need for hoses or compressors; include adjustable stainless steel trumpet support and mounting hardware. For the best sound use a set (One High Tone and One Low tone)