- +Two independently mounted horns with their own zinc bases, solenoids and 1/4 in airlines fit where rack-style train horns can't
- +Kleinn discloses PSI range, minimum tank size, both trumpet dimensions and the solenoid's 165 PSI ceiling
- +Low entry price for a real two-tone locomotive-style horn: $121.50 on sale, $142.95 regular
- +Replacement trumpets, base/driver and Model 307 solenoids sold individually by Kleinn
- +Same horns used in Kleinn's HK5 and vehicle-specific bolt-on kits; official audio sample available
- +Retailer owner reviews describe them as very loud for their size and easy to add to existing onboard air
- −ABS plastic trumpets rather than chrome or brass
- −151.8 dB rating published without a test distance
- −Kleinn quietly revised the rating and dimensions down from the 154.2 dB and 10.5/15.5 in figures retailers still show
- −No chord frequencies or weight disclosed
- −Only a 1-year warranty
- −Horn-only: needs a 140-160 PSI air system with at least a 1.5-gallon tank, plus wiring and a switch
Methodology
This review aggregates publicly available information from manufacturer specifications, retailer listings, and verified user reviews. We do not perform hands-on testing. Last reviewed: September 7, 2026. Our primary source is Kleinn’s official product page for the Model 220 “Mini Beast,” which Kleinn updated the same day we checked it. We cross-checked it against Kleinn’s component pages for the Model 307 solenoid and the replacement trumpets and base, the HK5 kit page that bundles these same horns, and retailer listings at Northridge4x4, Alligator Performance, Summit Racing and 4 Wheel Parts. User impressions come from retailer reviews and a Ford Truck Enthusiasts thread and are reported as owner opinions, not measurements. Every number below traces to a source in the list at the end.
Quick verdict
The Kleinn Model 220 “Mini Beast” is the bare-horn version of the HK5 kit: two black ABS trumpets with zinc bases, each fed by its own Vortex 4 (Model 307) 12-volt solenoid, rated by Kleinn at 151.8 dB at 150 PSI. We rate it 4.1/5. At $121.50 on sale ($142.95 regular) it is one of the cheapest ways to put a genuine two-tone locomotive chord on a truck, SUV or Jeep that already has onboard air, and the separate-mount design solves the packaging problem that keeps most train horns off small vehicles. The trade-offs are plastic trumpets rather than chrome or brass, a decibel figure published without a test distance, a spec sheet that Kleinn quietly revised downward from the numbers still circulating at retailers, and a 1-year warranty.
What it is
The Model 220 is a pair of individually mounted train horn trumpets, not a complete kit. Kleinn positions it as “the legendary Kleinn locomotive blast, reimagined for smaller rigs”: the brand says it is engineered for smaller trucks, SUVs and Jeeps where a full triple-horn rack will not fit. The two trumpets are different lengths so they produce a two-note chord, and because each one has its own base, solenoid and airline, you can tuck them into separate corners of a bumper or frame rail instead of finding one long flat mounting surface.
Kleinn sells the same horns inside its universal HK5 “Mini Beast” kit and inside the vehicle-specific GMTRK-3 and other bolt-on kits whose model numbers end in “-220” or “-XTREME.” Buying the 220 alone makes sense if you already own a compressor and tank, or want to build a custom air system rather than accept Kleinn’s 1.5-gallon HK5 package. For the kit version, see our Kleinn HK5 review, and for the rest of the lineup see the Kleinn reviews hub.
Kleinn brands its bells by series: the “Screamer” compact air horns use 3.5-inch bells for a high-pitched emergency-vehicle tone, while the train horn series, including the 220, 230 and 730, uses 6- to 7-inch bells to move more air for what the brand calls “the authentic tone of a 40,000-lb classic locomotive.” The 220 is the smallest, cheapest member of that train horn group and is sold only in black.
Specifications
All values are from Kleinn’s current product page unless noted. See the section on the spec revision below for the older numbers still shown by some retailers.
| Spec | Value |
|---|---|
| Model / part number | Kleinn Model 220 “Mini Beast” (SKU KL 220) |
| Horn type | Dual train horn, individual mount |
| Sound output | 151.8 dB at 150 PSI (test distance not disclosed) |
| Operating pressure | 140 to 160 PSI (Kleinn’s stated optimal range) |
| Solenoid | Two Model 307 Vortex 4 chrome 12-volt solenoids, 165 PSI maximum |
| Airline | 1/4 in OD, separate line to each horn |
| Small trumpet | 11.5 in L x 5 in W x 5 in H |
| Large trumpet | 16.25 in L x 6.25 in W x 6.25 in H |
| Construction | Composite ABS trumpets, zinc alloy bases |
| Finish | Gloss black trumpets, chrome solenoids |
| Chord frequencies | Not disclosed |
| Weight | Not disclosed |
| Minimum tank size | 1.5 gallon |
| Power source | Air tank plus 12 V for the solenoids |
| Warranty | 1 year |
| Price | $121.50 on sale (regular $142.95) at kleinn.com; $142.95 at Northridge4x4 and Alligator Performance |
- Rated output
- 151.8 dB at 150 PSI
- Trumpets
- 2, ABS, 11.5 in and 16.25 in
- Valves
- 2x Model 307 Vortex 4, 12 V
- Air needed
- 140 to 160 PSI, 1.5 gal minimum tank
- Warranty
- 1 year
The spec revision retailers have not caught up with
Kleinn’s own page now lists 151.8 dB at 150 PSI and trumpet lengths of 11.5 and 16.25 inches. Older copy that still appears at Alligator Performance and Northridge4x4 advertises “up to 154.2 dB” with trumpets of 10.5 and 15.5 inches. We treat the current kleinn.com figures as authoritative. Note also that the Model 307 solenoid page caps the valve at 165 PSI, so the 160 PSI top of Kleinn’s recommended range is a real ceiling, not a suggestion. Whichever number you see, it is a manufacturer claim measured at an undisclosed distance; our decibels guide and advertised vs. real dB guide explain why that matters.
What’s in the box
Per Kleinn’s “what’s in the box” list, this is a horn-only package:
- Two separate black high-impact ABS wide-bell trumpets with zinc alloy bases
- Two Model 307 Vortex 4 12-volt solenoid valves, one per trumpet
Not included: compressor, tank, pressure switch, airline, fittings, relay, horn button or wiring. Kleinn’s HK5 kit adds the 6275RC waterproof compressor, a 6275RT 1.5-gallon tank, a 2151 pressure switch, a FIT56 fitting pack, a horn button, thread sealant, 12 ft of 1/4 in air tubing and 12 ft of 3/8 in airline, and lists at $549.95 (on sale at $467.45 when we checked). That puts the air system’s share of the kit at roughly $345 to $400 more than the bare horns.
Pros
- Two independent horns with their own zinc bases, solenoids and airlines, so they fit in spaces no rack-style train horn can
- Kleinn discloses PSI, minimum tank size, both trumpet dimensions and the solenoid pressure ceiling, which is more than most horn-only listings offer
- Low entry price for a real two-tone locomotive-style horn: $121.50 on sale, $142.95 regular
- Replacement parts sold individually by Kleinn: small trumpet $46.70, large trumpet $50.95, base/driver $42.45, Model 307 solenoid $22.90
- Same horns Kleinn uses in its HK5 and several vehicle-specific bolt-on kits, and an official audio sample is available on Kleinn’s site
- Owner reviews aggregated by retailers describe them as very loud for their size and easy to add to an existing onboard air system
Cons
- ABS plastic trumpets rather than chrome-plated or brass; Kleinn’s Model 730 is the stainless steel step-up
- 151.8 dB rating is published without a test distance
- Kleinn revised the rating and dimensions downward from the 154.2 dB and 10.5/15.5 in figures many retailers still show, which can confuse buyers comparing listings
- No chord frequencies or weight disclosed
- Only a 1-year warranty, versus longer terms from some competitors
- Horn-only: you must supply a 140 to 160 PSI air system with at least a 1.5-gallon tank, plus wiring and a switch
Alternatives
- Kleinn Model 230 “Beast”: Kleinn’s triple-trumpet ABS train horn at $212.45, a fuller three-note chord for buyers with more mounting room. Read our Kleinn 230 review.
- Kleinn HK5 “Mini Beast” kit: the same 220 horns with Kleinn’s waterproof 6275RC compressor and 1.5-gallon tank. Buy this instead if you do not already own an air system. See our HK5 review.
- HornBlasters Shocker XL: the best-known competitor in the compact dual-tone class, sold both bare and in kits. See our Shocker XL review and the Kleinn vs. HornBlasters guide.
Install / compatibility notes
Kleinn’s requirements are explicit: compressed air, a minimum 1.5-gallon tank, and an optimal 140 to 160 PSI. The brand names its Model 6350 (150 PSI, 100% duty cycle) and Model 6450 (200 PSI, 100% duty cycle) onboard air systems as compatible, and the HK5 kit proves the smaller 6275 medium-duty system works too. Because the Model 307 solenoid is rated to 165 PSI, do not feed the 220 from a 200 PSI system without regulating pressure down; our air regulator guide covers how.
- Mount each trumpet by its zinc base. Kleinn’s marketing stresses that the two horns can go on separate sides of a bumper or in different corners of the frame. Angle the bells slightly downward so water drains; see our compressor and horn mounting guide.
- Run a separate 1/4 in OD airline from the tank (or a tee at the tank outlet) to each Model 307 solenoid. Each valve takes 1/4 in OD airline in and threads into the horn base with a 1/4 in male NPT outlet.
- Wire both solenoids to a single relay triggered by a momentary horn button or your factory horn circuit. Each 307 is a standard 12-volt coil; our amp draw, fuse and wire gauge guide has sizing guidance.
- Pressurize the tank to at least 140 PSI before the first test. Kleinn’s install PDFs, linked from the product page, cover the air system side.
Two practical notes from owner reports. One retailer reviewer called the horns “not as loud as the big three but easier to install in smaller spaces,” which matches Kleinn’s own positioning. A Ford Truck Enthusiasts thread on Kleinn installs (mostly the HK7 and SDKIT17-734 kits, not the 220 specifically) reports a straightforward install for owners with mechanical skills, plus one HK7 owner whose compressor blew fuses until the installing shop replaced the relay and fixed an air-line leak. Check your state’s rules before you drive with it; our legality guide and state pages explain where a train horn on a road vehicle is restricted.
Sources
- Kleinn — Model 220 “Mini Beast” Dual Black ABS Train Horns product page — current specs (151.8 dB at 150 PSI, 140-160 PSI, 11.5 in and 16.25 in trumpet dimensions, ABS/zinc construction, dual 307 solenoids, 1/4 in separate airlines, 1.5-gal minimum tank, 1-year warranty), box contents, compatible air systems, series positioning, price ($121.50 sale / $142.95 regular), install PDF links, and all four product photos’ source page
- Kleinn — Model 307 Chrome Solenoid Air Valve product page — Vortex 4 valve specs (12 V, 1/4 in OD airline in, 1/4 in M NPT out, 165 PSI maximum) and $22.90 price; solenoid photo
- Kleinn — Replacement ABS Trumpets for Model 220 Mini-Beast — replacement small ($46.70) and large ($50.95) trumpet prices; trumpet photos
- Kleinn — RP-230/730 Base replacement driver for Model 220/230/730 — $42.45 replacement base
- Kleinn — Model HK5 Universal “Mini Beast” Dual ABS Train Horn System — kit contents (6275RC compressor, 6275RT 1.5-gal tank, 2151 switch, FIT56 fittings, tubing) and price ($549.95 regular, $467.45 sale)
- Kleinn — Model 230 “Beast” ABS Triple Train Horns — $212.45 price used in Alternatives
- Kleinn — Horn audio samples page — confirms an official Model 220 audio sample exists
- Kleinn — 6350/6450 onboard air system installation manual (PDF) — air-system install reference linked from the 220 product page
- Northridge4x4 — Kleinn Model 220 Train Horn listing — $142.95 retail price, older “154.2 db output” claim, 1-year limited warranty, dual Vortex 4 solenoids
- Alligator Performance — Kleinn 220 Black Dual Train Horn Kit — $142.95 price and older spec copy (“up to 154.2 dB,” 10.5 in and 15.5 in trumpets)
- Summit Racing — Kleinn 220 Dual Train Horns (KLN-220) — retailer availability cross-check
- 4 Wheel Parts — Kleinn Model 220 Dual Train Horns — retailer listing with owner reviews (“not as loud as the big three but easier to install, in smaller spaces”)
- Amazon — Kleinn Air Horns 220 Dual Train Horn customer reviews — owner impressions on loudness and install (“ridiculously loud for their size”)
- YouTube — “Kleinn Model 220 Dual Train Horn” (AutoTruckToys.com) — retailer sound demo of the 220
- YouTube — “KLEINN GMTRK-3 Train Horn Kit With Model 220 Dual Train Horns” (Kleinn) — Kleinn’s own demo of the 220 horns inside a GM bolt-on kit
- Ford Truck Enthusiasts — “Kleinn Air Horn Installation” thread — owner install reports for Kleinn kits (HK7, SDKIT17-734), including one compressor fuse/leak repair, cited as user experience only
Train Horn Hub aggregates publicly available data. We do not test products in-house. All trademarks belong to their respective owners.
The right pick for truck, SUV and Jeep owners who already have onboard air and need a genuine two-tone train horn that fits in tight spaces for well under $150; buyers without an air system should price the HK5 kit instead, and anyone who wants metal trumpets should step up to the Model 730.
Frequently asked questions
Quick answers to the questions people ask most about this topic.
- How loud is the Kleinn Model 220 Mini Beast really?
- Kleinn currently rates the Model 220 at 151.8 dB at 150 PSI. That is a manufacturer claim published without a test distance, so treat it as a marketing figure rather than a distance-qualified measurement. Some retailers still show an older 154.2 dB claim that Kleinn no longer uses.
- Does the Model 220 come with a compressor and tank?
- No. The box contains only the two ABS trumpets and two Model 307 Vortex 4 solenoids. Kleinn says you need a compressed-air system running 140 to 160 PSI with at least a 1.5-gallon tank. The HK5 kit bundles the same horns with a 6275RC compressor and 1.5-gallon tank.
- Why do some listings say 154.2 dB and 10.5/15.5-inch trumpets?
- That is older Kleinn spec copy. Kleinn's current product page lists 151.8 dB at 150 PSI and trumpet dimensions of 11.5 in and 16.25 in. Retailers such as Alligator Performance and Northridge4x4 have not updated their listings, so go by kleinn.com.
- What size airline and solenoid does the 220 use?
- Each trumpet has its own Model 307 Vortex 4 12-volt chrome solenoid that accepts 1/4 in OD airline and threads into the horn base with a 1/4 in male NPT outlet. Kleinn rates the 307 at a maximum of 165 PSI, so regulate a 200 PSI system down before feeding these horns.
- Is the Kleinn 220 a good value compared with the HK5 kit?
- If you already have onboard air, yes: the horns alone are $121.50 on sale or $142.95 regular, versus $467.45 on sale ($549.95 regular) for the HK5 kit with the same horns plus compressor, tank, switch and fittings. If you have no air system, the kit's roughly $345 to $400 premium is about what a comparable compressor and tank would cost separately.
