HornBlasters train horns are of the finest quality. On top of being virtually indestructible, they're covered with an amazing warranty. They also feature stainless-steel diaphragms which not only resist the elements but endure the harshest high-pressure conditions. The tuning of the horns is musically accurate. Each horn is tuned to a specific note and is accurate to 1 Hz. Together the horn kits play easily recognizable, authentic locomotive chords. HornBlasters horns must all pass inspection in an anechoic chamber before leaving the factory. All HornBlasters kits feature DOT/SAE J10/ASME spec. airline and fittings. These rugged American safety standards not only insure your safety but also reflect the durability of these kits. These kits feature standard pipe threading and line sizes. This means you won't have any trouble finding parts at any American hardware store. All ports and fittings are NPT. The air valves and air compressors used are brand name and of the highest quality. The Viair compressors used in kits are the industry-leading onboard air compressor. HornBlasters does not use any generic parts in their kits. Everything used is both of the highest quality and hand-selected to be used in HornBlasters kits.