The Nathan K5LA is the god father of all train air horns! Still in use today, the Nathan K5 is used on commercial locomotives all around the country. This Airchime train horn is of the highest quality construction and guarantees amazing performance! The K5 incorporates five heavy duty die-cast kettle drum bells with a high flow five way manifold. The K5LA horn is the real deal: not only is it the loudest horn we've ever sold, but a genuine locomotive air horn. It doesn't imitate the sound you hear from diesel locomotives; it is the sound you hear from diesel locomotives. You'll be heard for miles with a set of these horns!