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HornAir 444K Nightmare Edition Onboard Air System

Honking & Capable Onboard Air System


Add Tire Inflation Kit Tooltip
Our Tire Inflation Kit includes a 30' Coil Hose, Tire Inflation Gun, & Air Relocation Kit!
Add 220 PSI Digital Pressure Gauge Tooltip
Using a tank mounted sensor wired directly to your gauge, our 220-PSI rated Digital Air Pressure Gauge delivers unparalleled accuracy with microprocessor stabilized readings.
Add Cooling Fan Isolator Kit Tooltip
Isolate your Compressor, drastically cutting down on vibration, allowing your compressor to run quieter & cooler, & extending the duty cycle up you 25%!
Add 444C Dual Air Compressor Upgrade Tooltip
Double your performance with the 444C Dual Compressor upgrade. Recharge your tank faster and honk more often. Great for air tools and other air source needs as well.
Add Gold Extended Warranty Tooltip
1 year add-on to existing warranty. Does NOT cover accidental damage, no advanced replacement.
Click here for more information!
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Add Platinum Extended Warranty Tooltip
2 year add-on to existing warranty. DOES cover accidental damage and advance replacement.
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If you need an onboard air system with big capacity and power in a smaller package, you've found the right kit, the HornAir 444K is what you're looking for. Not only is the HornAir 444K great for train horns, but this constant duty system also packs enough power to meet and exceed many pneumatic needs. Our Nightmare edition comes with a stealth black finish on the Viair 444 air compressor to give the system a clean and low-profile look.

Included is our matching black 4-gallon pancake air tank that has four 1⁄2” ports on top, two 3⁄8″ ports on top, one 1⁄8” port on top, and one 1⁄4” port on the bottom. Strategic placement of the ports allows you to be able to install your drain cock on the bottom-most port on the tank for optimal draining no matter how the air tank is oriented. The ½ inch ports provide optimal airflow, preventing bottlenecking that occurs in other kits. This tank is great for stashing in a wheel well or other areas you need a 4-gallon tank in a tight spot. 

The stealth black Viair 444C that comes with our Horn Air 444K is a constant-duty compressor that was built to handle a heavy workload. With a 100% duty cycle at 100 PSI and a recharge time from 110-150 PSI of just less than a minute, the HornAir 444K makes sure you always have the air that you need. The 444C is part of a new generation of compressors that feature a brand new, patent-pending, intercooler head design that helps disperse heat much more efficiently.

An increasing number of people are using this for more than just blasting horns! With a system like the HornAir 444K, you can also use the air supply to:

  • Adjust tire pressure
  • Moderate pneumatic use
  • Inflate water toys and safety gear
  • Supply air to load leveling bags
  • Supply air for differential lockers
  • Blow up kids toys
  • And lots more!

While the HornAir 444K is a complete onboard air system that provides you with everything you need to get up and going, be sure to add a wireless remote, tire Inflation Kit, or an electric drain valve kit to get the most out of one of the best onboard kits you can buy!

Our HornAir systems come complete with all necessary fittings, including a Viair 110/150 Pressure Switch with a built-in relay, safety blow-off, air gauge, and drain cock. Unlike many other onboard air systems, ours comes with 10 and 18 gauge wire, as well as a complete wiring kit including a fuse holder. This takes out the guesswork and helps ensure your system is installed correctly. All of our kits are also backed by a one year manufacturer's defect warranty as well as lifetime tech support!    

      0 1.76 13 0 100.0 13
      10 1.63 14 1.0 88.5 15
      20 1.49 16 2.0 81.3 16
      30 1.43 17 3.0 75.6 17
      40 1.36 17 4.0 70.6 18
      50 1.29 18 5.0 65.5 18
      60 1.24 18 6.0 59.0 19
      70 1.18 18 7.0 53.1 20
      80 1.10 19 8.0 47.7 19
      90 1.02 19 9.0 43.2 19
      100 0.95 20 10.0 38.8 19
      110 0.87 20 11.0 34.7 18
      120 0.83 19 12.0 30.6 18
      130 0.77 19 13.0 25.8 17
      140 0.71 19 14.0 23.8 16
      150 0.66 19
      160 0.61 18
      170 0.57 18
      180 0.50 17
      190 0.45 17
      200 0.43 16

      * Supply voltage: 13.8 volts

      • All-inclusive train horn air solution!
      • Top-end 150 PSI compressor perfect for train horns
      • Comes with a standard 1/2" push-to-pull fittings
      • Complete fitting kit with safety valve & drain cock
      • All standard mounting hardware
      • Part Number: HA-444K
      • Operating Pressure: 150 PSI
      • Restart Pressure: 110 PSI
      • Voltage: 12-Volt DC
      • Tank Part Number: TA-4P
      • Volume: 4 gals (15.14 L)
      • 1/4" NPT Ports: 1
      • 1/2" NPT Ports: 4
      • 3/8" NPT Ports: 2
      • 1/8" NPT Ports: 1
      • Tank Length: 16″ (406.4 mm)
      • Tank Width: 16″ (406.4 mm)
      • Tank Height: 8″ (203.2 mm)
      • Air Compressor: Viair 444C black air compressor
      • Max Amperage: 19 Amps
      • Maximum Duty Cycle: 100% @ 100 PSI
      • CFM @ 0 PSI: 1.76 CFM
      • Compressor Length: 11.25″ (285.75 mm)
      • Compressor Width: 4.0″ (101.6 mm)
      • Compressor Height: 6.75″ (171.45 mm)
      • Compressor Weight: 9.75 lb (4.42 Kg)
      • Money-Back Guarantee/Refund Policy
        All merchandise unless otherwise indicated may be returned within 30 days from the shipment arrival date for a refund. A Returned Merchandise Authorization (RMA) number is required for all returns. A 15% restocking fee may apply. Additional deductions may be made to reflect the products current market value. These terms apply to all refunds. Most products are shipped with a refund/replacement guarantee period unless otherwise noted in the product listing. Customers must inform of any order discrepancy within 7 days from the invoice date so that we may investigate and resolve the situation accordingly.
      • Warranty
        This product is backed by our one-year manufacturer's defect warranty!
      • Satisfaction Guarantee offers our customers a 30-day satisfaction replacement or refund guarantee on all purchases, except when otherwise noted in the product listing.
      • Cross-Shipments will not cross-ship returned merchandise.
      • Physical Damage Policy
        Physical damage to any product purchased at will effectively void warranty coverage. Physical damage includes but is not limited to improper handling and/or any other type of damage sustained by irregular usage.

      Warnings & Notices

      Safety warning icon

      This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to

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