Iconic sound: The Flatlaw Train Horn delivers the same commanding sound as the original Outlaw train horn, but with the added benefit of being able to mount in more vehicle types thanks to its side-by-side bell configuration. High-quality construction: Made with durable metal alloy and expert craftsmanship, the Flatlaw Train Horn is built to last and will hold up to the demands of heavy use over time. Quick and easy installation: The bells are arranged side-by-side for easy mounting in a variety of vehicle types, and the included pre-installed 3/8" valve makes installation quick and easy. Must be paired with an air source! This horn does not function off of electricity. You must have an existing onboard air system to use this horn! Loud and popular: The Flatlaw Train Horn is one of the loudest and most popular train horns we carry. Its low, deep, and full sound is sure to turn heads and make a statement on the road. Experience the unmatched power and distinctive sound of the HornBlasters Flatlaw Train Horn. With its innovative design and commanding presence, this horn takes the iconic Outlaw Train Horn to new heights.