Model HK9-Slimline: Universal "Demon™" Triple Steel Train Horns / Onboard Air System

Skip to product information

KL HK9-Slimline

Regular price $1,149.95
Sale price $1,149.95 Regular price

💳 Get it today, pay over time with Shop Pay Installments.

In stock

PROP 65 WARNING:
This product can expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.

Model 730: The Demon™ Triple Steel Train Horns

The Undisputed King of the Road

When the situation demands more than just a loud horn, the Demon 730 stainless steel horns dominate the road! Delivering a sonic roar that cuts through sirens, heavy machinery, and chaotic traffic, these precision tuned steel horns are the ultimate train horn solution. Engineered to move massive volumes of air, the 730 provides the deep, earth-shaking rumble of an authentic 40,000-lb locomotive.

XCR 2.0™ Extreme Durability

Featuring our signature XCR 2.0™ salt-spray resistant coating, the Demon 730 thrives in the harshest environments. Whether faced with coastal salt air or off-road mud, these horns are built to maintain their professional-grade finish and startling output for the long haul. The stainless steel construction ensures that the internal components won't succumb to the corrosion that destroys lesser horns.

Modular Mounting Flexibility

While the Demon 730 comes mounted on a heavy-duty flat rack, it offers maximum installation flexibility. Each individual trumpet can be removed from the rack and mounted separately to accommodate even the tightest installation requirements on trucks, SUVs, or Jeeps. This modular architecture allows you to tuck the massive 6" to 7" bells into locations where a fixed-rack system simply won't fit.

why choose the "Demon" 730 horns?

  • Unmatched Volume & Airflow: The undisputed crown jewel of the Kleinn lineup and our loudest stainless-steel triple train horn.
  • Heavy-Duty Construction: Built with precision-tuned stainless steel trumpets for the most aggressive locomotive roar available.
  • All-Weather Reliability: Signature XCR 2.0™ black coating provides extreme salt-spray and corrosion resistance.
  • High-Flow Solenoid: Pre-fitted with a professional-grade VX6003 heavy-duty brass solenoid for instantaneous response and maximum decibel output.
  • Universal Integration: Designed to work with any high-pressure air system (150 PSI recommended) to command immediate attention.
  • Modular Architecture: Detachable horns allow for custom mounting configurations tailored to your specific vehicle chassis.

the Undisputed King of the Road!

THE VERDICT: Designed specifically for those who want to dominate the road, the 730 Demon™ is your weapon of choice. It stands as the largest and loudest train horn in the Kleinn arsenal.

 

WHAT'S IN THE BOX?

  • (730) The Demon™ stainless steel triple train horns: Precision-tuned trumpets on a detachable flat rack.
  • (VX6003) High performance air solenoid valve: Pre-installed 1/2" NPT heavy-duty brass air valve.
  • (Fitting) 1/2" Airline Connector: Compression fitting for high-flow air delivery.
  • Installation Hardware: Heavy-duty mounting bolts and high-strength fasteners.

 

BOOST YOUR BLAST: 30% MORE OUTPUT

Unleash the full fury of your Demon™ 730 Train Horns!

Experience the Demon™ 730 Horns in all their glory! The Ultra BlastMaster™ (6890) re-engineers your system’s architecture, maximizing airflow to deliver a devastating, high-decibel blast. It’s simple physics: more air equals more output. We ditched the standard 3/8” lines in favor of massive, dedicated 1/2” airlines leading to three High-Flow VX6003 brass solenoids—one for every individual horn.

This isn't just an upgrade; it’s a shocking twist on a classic, delivering soul-shaking locomotive blasts that command immediate attention. Overwhelm the senses and dominate the streets with the absolute peak of train horn intensity at your fingertip.

TOO LOUD? TOO BAD!

Air Horns vs. Train Horns

Find Your Signature Blast

The Screamer

Compact Air Horn Series

Engineered for "Emergency Vehicle" authority. This series delivers a sharp, high-frequency blast designed to cut through ambient noise instantly. With 3.5" bells, these horns produce a piercing scream that commands attention in heavy traffic.

Classic Chrome
  • Compact Horns: 102 / 130 / 141
  • Kits: HK2 / HK3 / HK4
Stealth Black
  • Compact Horns: 101 / 102-1 / 130-1 / 141-1
  • Kits: HK1 / HK2-1 / HK3-1 / HK4-1 / HKUTV / Vehicle Specific Kits: 102, 102-1
The Deep Rumble

Train Horn Series

Don’t just make noise—make an impact. Engineered with massive 6-7" bells, our Train Horns move huge volumes of air to create a deep, earth-shaking rumble. This is the authentic tone of a classic 40,000-lb locomotive.

Classic Chrome
  • Train Horns: 500 / 501 / 502 / 630
  • Kits: HK6 / HK8
Stealth Black
  • Train Horns: 220 / 230 / 730
  • Kits: HK5 / HK7 / HK9 / HK9-Slimline

Professional-grade engineering. Legendary Kleinn Performance.

 

 Train Horn Specifications

Triple ABS Train Horns

 

Part Number

Model (230) “The Beast"

Number of horns

3 (Flat Rack or Individual Mount)

Warranty

1-Year Warranty

Construction

Composite Black ABS Trumpets

Heavy Duty Brass Solenoid (12-Volt)

P/N- VX6003 (51438 & 53814N Fittings Incl.)

Max Pressure

150 PSI

Output (dB) @ 150 PSI

155.1dB (156.9 dB w/ 6885 Upgrade Kit)

Dimensions (On Flat Rack Bar)

18.5” L x 18” W x 7” H

Dimensions (Each Individual Horn)

18.5” Lg. – 16.5” Med. - 14.5” Sm.

Minimum Tank Size Required

2.5-Gallon

Airline Length and Size Included

12’ of ¼” OD Airline

Upgrade kit compatibility

Use Model 6885

 

Air Compressor Specifications

Ultra Heavy-Duty Air Compressor

 

Part Number

Model (6450RC)

Warranty

2-Year Extended (6450RC, 6650RC, & 730)

Compressor Type

Waterproof Sealed, Oil-less

Motor Type

Permanent Magnetic Motor

Waterproof & Submersible

Sealed Internally (Must install “Snorkel” system)

Compressor “Snorkel Kit”

Remote Air Filter Relocation Kit- 12' 3/8” Airline

Voltage

12-Volt DC

Duty Cycle

100% @ 100 PSI (@ 72° F)

Flow Rate

@ 0 PSI (13.8 Volts): 2.5 CFM

Max Pressure

200PSI

Max Amp Draw

23 Amps

Dimensions

11.25” L x 4” W x 6.50” H

Mounting Holes

8.90” L x 3.31” W (5mm Diameter)

Mounting Note

Do not mount upside down

Pressure Switch

P/N 2151 (Works with 52175 Safety Valve)

 

Air Tank Specifications

3-Gallon Slim Air Tank

 

Part Number

Model (6351RT)

Warranty

1-Year

Tank Capacity

3-Gallon

Construction

All Steel Design (Gloss Black Epoxy Finish)

Internal Coating

Cortec Internal Anti-Corrosion Coating

Mounting Legs

2 Legs w/ 4 Mounting Points

Air Tank Ports

5 - 1/4" NPT Ports & 1 - 3/8" NPT Ports

Mounting Hardware

Fitting Pack - 4 Bolts, Nuts, Washers

Max Pressure

200 PSI

Dimensions

27” L x 6” W x 8” H

 

Air Tank Fill Rates

Tank Capacity

Tank Pressure Range

Tank Fill Rate

2.5 Gallon

0 - 150 PSI

2 Min. 54 Sec. (+/- 10 Sec.)

2.5 Gallon

110 - 150 PSI

54 Sec. (+/- 5 Sec.)

5 Gallon

0 - 150 PSI

5 Min. 57 Sec. (+/- 10 Sec.)

5 Gallon

110 - 150 PSI

1 Min. 53 Sec. (+/- 5 Sec.)

 

Installation Instruction Links:

Model HK9-Slimline: Universal "Demon™" Triple Steel Train Horns / Onboard Air System

$1,149.95

Does it come with a warranty?

One-Year Limited Defect Warranty for Kleinn Automotive Accessories:

Kleinn Automotive Accessories is committed to delivering high-quality products to our customers. We stand behind the craftsmanship and materials of our products by offering a comprehensive one-year limited warranty. This warranty is extended to the original purchaser, ensuring that when our products are installed properly and used under standard conditions, they will be free from defects in workmanship and materials for a period of one year from the original date of purchase.

This warranty encompasses a promise that the product you have purchased will perform as expected under normal use conditions and will not suffer from flaws in materials or craftsmanship. However, it is important to note that this warranty does not cover any damage that results from abusive use, operation that is not in line with the product’s intended purpose, or harm resulting from exposure to harsh environmental conditions. In the event that a product is found to be defective within the warranty period following a thorough inspection, Kleinn Automotive Accessories reserves the right to either repair or replace the defective item at no additional charge to the purchaser. It is our goal to ensure that our products meet the high standards that our customers expect, but we also want to clarify that Kleinn is not responsible for covering any costs related to the installation of our products, nor are we liable for any loss or damage that may occur as a result of the repair or replacement process of any product under warranty.

Extended Two-Year Warranty for Select Products:

Understanding the specific needs of our customers and the demands placed on certain products, Kleinn Automotive Accessories is pleased to offer an exclusive extended two-year warranty for our 6450/6650 Compressors and 730 Horns. This special warranty extension reflects our confidence in these products’ durability and performance. Eligible products under this extended warranty will enjoy all the benefits of our standard one-year warranty with an additional year of protection, totaling two years from the date of purchase. This extended warranty coverage ensures that these specific models, recognized for their robustness and reliability, receive the extra assurance customers desire for these critical components.

Detailed Warranty Return Procedure:

Should you need to initiate a return under the warranty, we have a straightforward process designed to make it as convenient as possible for our valued customers. To start, you will need to email a copy of your sales receipt, which must be dated within the past year for standard warranty claims or within the past two years for claims under the extended warranty for the 6450 Compressors and 730 Horns. This email should be directed to our Warranty Manager and include your full name, email address, telephone number, and a concise description of the problem you are experiencing.

Upon receipt of your email, a dedicated representative from Kleinn Automotive Accessories will reach out to you directly. Our first step will always be to attempt to resolve the issue through technical support, aiming to provide a quick and effective solution. If the problem cannot be addressed remotely, our representative will issue a Return Authorization number. This number is crucial as it will identify your return throughout the inspection process. You are then required to send the product back to Kleinn Automotive Accessories for a comprehensive physical inspection.

Upon inspection, if the product is determined to be defective due to issues in workmanship or materials, Kleinn will undertake to either repair or replace the product at our discretion. We are committed to ensuring that our customers receive products that meet our high-quality standards, and we will make every effort to resolve warranty claims to your satisfaction. However, if the inspection reveals that the product does not have a material defect, we will return the unit to the customer. In such cases, the shipping costs for the return will be the responsibility of the customer.

Kleinn Automotive Accessories
4045 N. Highway Drive, Tucson, AZ 85705
Tel (520) 579-1531

What's the returns policy?

How To Return An Item

Your item must be in its original unused condition to be returned, unless there is a manufacturer defect. You must return the item within 30 days of your purchase.

1. Please email support@kleinn.com to request a refund and we will assign you a Return Authorization #.

2. Mail your returned item to:
Kleinn Automotive Accessories
Returns Department
4045 N Highway Drive
Tucson, AZ 85705

3. Include in your package a signed letter stating the reason for your return and the original receipt.

Return Non-Exceptions

Merchandise that has been worn, used, or altered will not be accepted for return or exchange.

Restocking Fee

All returns are subject to a 15% restocking fee, which will be deducted from your refund. If shipping and handling fees were applied to your order, they are non-refundable.