By Wolo, these chrome ABS air horns are perfect for any 12 volt system. Kit has 2 durable plastic trumpets with a bright chrome plated finish, a chrome plated compact maintenance free compressor, all mounting hardware to easily install on any bike. Instruction are in English and Spanish. 120 Decibels-620/740 Hz. Pair. Optional Weather Protection Cap sold separate, Add On part 415WPC, $14.95.