The SDKIT17-734 includes a Direct-Fit onboard train horn system, featuring the model 730 Demon triple train horn, 3-gallon air tank, 6450RC Heavy Duty 100% duty cycle high output waterproof air system. The kit can be upgraded to be even LOUDER by adding a P/N 6890 Ultra BlastMaster Valve Upgrade Kit. System also includes a quick connect tire inflator with storage bag. Kleinn vehicle specific train horn kits are also available as a stand alone onboard air system without a horn.