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

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KL HK9-Slimline

Regular price $1,034.95
Sale price $1,034.95 Regular price $1,149.95

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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.
  • 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.

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.

Classic Chrome
  • Compact Horns: 102 / 130 / 141
  • Kits: HK2 / HK3 / HK4
Stealth Black
  • Compact Horns: 101 / 102-1 / 130-1
  • 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 Steel Train Horns
Part Number Model (730) “The Demon"
Number of Horns 3 (Flat Rack or Individual Mount)
Warranty 2-Year Warranty
Construction Stainless Steel Trumpets
Brass Solenoid P/N VX6003 (12-Volt)
Max Pressure 200 PSI
Output (dB) 157.8 dB (159.6 dB w/ 6890 Upgrade Kit)
Rack Dimensions 22.5” L x 18.5” W x 7.25” H
Trumpet Lengths 21.75”, 17.75”, 13.5”
Airline Size 1/2" OD Airline
Air Compressor Specifications
Feature Feature Details
Part Number Model 6450RC
Warranty 2-Year Extended (6450RC, 6650RC, & 730)
Max Pressure 200 PSI
Duty Cycle 100% @ 100 PSI (@ 72° F)
Flow Rate @ 0 PSI (13.8 Volts): 2.5 CFM
Compressor Type Waterproof Sealed, Oil-less
Voltage 12-Volt DC
Motor Type Permanent Magnetic Motor
Max Tank Size 7.0 Gallon
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 Mountable in any position except upside down
Shipping Weight 12 lbs
Pressure Switch P/N 2151 (Works with 52175 Safety Valve)
Air Tank Specifications
Slim Mount Air Tank 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 Five - 1/4" NPT Ports & One - 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 Pressure Range 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 Links:

Air Horn Kit Instructions

730 Horn Disassembly

Solenoid Wiring Diagram

Compressor Manual

Compressor Wiring Diagram

6890 BlastMaster Upgrade Diagram

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

$1,034.95

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.