Exterior Components› Grilles

Kleinn Air Horns

Demon Series Train Horn and Onboard Air System

$1,299.95

SKU: KL GMHD20-734

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Kleinn KL GMHD20-734 is a vehicle-specific, direct-fit train horn and onboard air system designed for 2020-2026 GM 2500HD and 3500HD trucks. This system features the Demon series stainless steel train horns paired with a 200 PSI, 100% duty-cycle waterproof air compressor and an anti-corrosion internal-coated steel tank.

It requires no drilling, cutting, or welding, and allows for the retention of the factory spare tire.
Show original supplier description
The Kleinn KL GMHD20-734 provides an aggressive, locomotive-style train horn blast and high-capacity onboard air performance for 2020-2026 GM 2500HD and 3500HD trucks. The kit includes the flagship 730 series stainless steel horns and a 200 PSI, 100% duty-cycle submersible waterproof compressor, ensuring long-term reliability in harsh under-vehicle environments. The system utilizes 1/2-inch air lines for maximum flow and volume. Included with each system are a 24-foot high-pressure kink-resistant air hose, a luminescent tire inflator gauge, and an air coupler relocation kit, effectively transforming the truck into a mobile air service station. It also features an automatic pressure switch, complete wiring, and all necessary mounting hardware for a professional installation. The 734 system includes an extended 2-year warranty on the compressor and horn assembly.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

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Specifications

BrandKleinn Air Horns
Part NumberKL GMHD20-734
CategoryExterior Components
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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