- +Complete kit for $399.99, only about $150 more than the Rhino horn alone
- +Detailed spec sheet with pressures, amperage and a fill-rate table
- +Pre-installed 1/4 in. electric valve simplifies plumbing
- +2-year kit warranty plus 30-day satisfaction guarantee
- +Compact M3 air source (about 16.5 x 4.9 x 7.1 in.)
- −Only 2-3 seconds of honk, then about 35 seconds to recharge
- −M3 air source isn't weather resistant and must be mounted upright and enclosed
- −Detaching the compressor from the tank voids the warranty
- −No published decibel rating or chord frequencies
- −120 PSI air source runs below the horn's listed 150 PSI max
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 28, 2026. Our primary source is HornBlasters’ official Rhino Black 3 Liter Train Horn Kit product page (part number HK-Q3-M3), including its spec table, fill-rate table, included-items list and warranty terms. We cross-checked it against HornBlasters’ standalone Rhino Train Horn page, the Mini Outlaw 3 Liter kit page (same M3 air source), HornBlasters’ page on decibel ratings, and retailer listings at Big Rig Chrome Shop and eBay. Every URL is listed in the Sources section at the end.
Quick verdict
The Rhino 3 Liter kit is a budget-friendly way to put HornBlasters’ three-chime Rhino horn on a vehicle. It’s a complete bolt-in package for $399.99 direct, against a $529.97 compare-at price. HornBlasters pairs the full-size Rhino horn with its compact M3 3-liter compressor-and-tank combo. That keeps the price down and makes it easy to package, but you only get 2-3 seconds of honk before a roughly 35-second recharge. We rate it 3.9/5. The spec sheet is detailed and honest, the 2-year kit warranty is solid, and owners rate it highly on HornBlasters’ own site. Points come off for the short honk, the strict indoor-mounting rule on the air source, and the lack of any published decibel or chord figure.
What it is
The Rhino is a three-trumpet train horn in HornBlasters’ “Stealth Black” finish. The kit copy describes it as a “3-chime copper” design. It is the same horn HornBlasters sells on its own as the Rhino Train Horn (part AH-Q3, $249.99 horn-only). As a horn, the Rhino is fairly large: 16.75 in. long, 15 in. wide and 11.25 in. tall, at 14.2 lb. HornBlasters’ marketing talks up a “deep, resounding tone” and a “genuine train horn sound”. Treat that as the brand’s description, since no chord frequencies are published.
The “3 Liter” part of the name refers to the air source. The M3 is a 12-volt compressor bolted directly to a 3-liter tank, sold as one unit. HornBlasters uses it as the entry air system for several kits, including the Mini Outlaw. The kit’s pitch is aimed at buyers who “want to make some noise without breaking the bank”. HornBlasters tags it for full-size pickups, mid-size pickups and SUVs. In our editorial reading, it suits someone who wants occasional short, loud blasts for fun or attention at a lower price. It is not meant for long, sustained pulls.
Kit price minus the horn-only price shows the value. At $399.99 versus $249.99 for the standalone Rhino (which already includes a valve and 12 ft of air line), the M3 air source, wiring and switch gear add about $150 in total. For HornBlasters’ full lineup, see our HornBlasters brand hub.
Specifications
| Spec | Value |
|---|---|
| Part number | HK-Q3-M3 |
| Horn | Rhino train horn, three chimes, black finish |
| Horn dimensions | 16.75 in. L x 15 in. W x 11.25 in. H |
| Horn weight | 14.2 lb (6.44 kg) |
| Horn max pressure (standalone AH-Q3 listing) | 150 PSI |
| Valve | Pre-installed 1/4 in. electric air valve |
| Air source | M3 3-liter air compressor and tank combo |
| Operating pressure | 120 PSI |
| Restart pressure | 90 PSI |
| Honk time | 2-3 seconds |
| Recharge, 90 to 120 PSI | 35 sec. (± 5 sec.) at 13.8 V |
| Full fill, 0 to 120 PSI | 2 min. (± 10 sec.) at 13.8 V |
| Air source dimensions | 16.535 in. L x 4.921 in. W x 7.086 in. H |
| Voltage | 12 V DC |
| Max amperage | 18 A |
| Decibel rating | Not published by HornBlasters |
| Chord frequencies | Not published |
| Weather resistance | Air source is not weather resistant |
| Warranty | 2-year manufacturer’s defect warranty on kit components |
| Price | $399.99 (compare-at $529.97) |
The kit page lists slightly different metric conversions for the horn (405 x 365 x 265 mm) than the standalone Rhino page (425.45 x 381 x 285.75 mm). The inch figures match on both, so we used those.
Older retailer listings copy an earlier version of the spec sheet. Big Rig Chrome Shop, for example, still shows 110 PSI operating and 85 PSI restart pressure. HornBlasters’ current page lists 120/90 PSI. We used the manufacturer’s current figures throughout, and we suggest you trust the official page over third-party copy.
What’s in the box
Per HornBlasters’ included-items list, the kit is complete and needs no extra parts for a basic install:
- Rhino Stealth Black train horn
- 3-liter compressor and tank combo (M3 air source)
- 12 ft of 1/4 in. air line
- Pre-installed 1/4 in. electric air valve
- 22 ft of 10-gauge red wire and 22 ft of 18-gauge blue wire
- Inline fuse holder, toggle switch, relay and all electrical terminals
- All fittings and mounting hardware
- Detailed instructions
- Earplugs
Pros
- Complete kit at a low price. At $399.99 you get horn, air source, valve, air line, wiring, relay, switch and hardware. That is only about $150 more than the Rhino horn on its own.
- Transparent spec sheet. HornBlasters publishes operating and restart pressure, amperage, honk time, and a fill-rate table with the supply voltage and tolerances. Many budget kits skip that level of detail.
- Valve comes pre-installed. The 1/4 in. electric valve is already on the horn, which removes one of the fiddlier plumbing steps.
- 2-year kit warranty. That is double the 1-year warranty on the standalone Rhino horn. HornBlasters’ 30-day satisfaction guarantee also applies.
- Strong owner feedback. HornBlasters’ product page shows a 5.0 average across 77 reviews. That is on-site feedback, not independent testing, so treat it as a signal only.
- Compact air source. The M3 unit is only about 16.5 x 4.9 x 7.1 in., so it fits behind a rear seat or in a bed box where a separate compressor and tank would not.
Cons
- Short honk. HornBlasters quotes 2-3 seconds of honk per tank, then about 35 seconds to recover from 90 to 120 PSI. It is a burst horn, not a sustained one.
- Air source isn’t weather resistant. HornBlasters says the tank-mounted compressor is not fully sealed. It must be mounted upright in an enclosed space away from moisture and dirt, or the warranty is void.
- No split mounting. Detaching the compressor from the tank voids the warranty. HornBlasters points buyers who need a remote compressor to its 232 and larger kits.
- No published dB or Hz figures. You can’t compare its output on paper with rivals that publish decibel ratings. HornBlasters argues that such ratings are often misleading.
- Air source sets the limit. The standalone Rhino is listed for up to 150 PSI, but the M3 stops at 120 PSI, so the kit doesn’t run the horn at its listed maximum.
- Outdated retailer copy. Some resellers still list 110/85 PSI, which can confuse shoppers comparing listings.
Alternatives
- HornBlasters Mini Outlaw 3 Liter kit: $369.99 with the same M3 air source and the same 120/90 PSI pressures, but a smaller three-bell horn. Or step up to the weather-resistant Mini Outlaw 127H ($399.99), which is sealed and gives 4-5 seconds of honk from a 1.5-gallon tank. At the same price as this Rhino kit, the 127H is the better choice if the air system has to live under the vehicle.
- Kleinn HK3 ProBlaster: about $439.95 direct for a complete triple-horn kit with a 130 PSI compressor and a 1-gallon tank. It costs a little more and has a separately mounted air system.
- HornBlasters Shocker XL: a much bigger commitment. It uses four trumpets and larger air systems for buyers who want sustained pulls rather than short bursts.
If you like the Rhino horn itself but need longer honks, compare it with the discontinued Rhino 544 pairing to see how a 5-gallon system changes the experience. Our air tank size guide shows how tank volume maps to honk time.
Install / compatibility notes
The kit is built for 12-volt vehicles. HornBlasters lists 12 V DC and a maximum draw of 18 A, and the included 10-gauge power wire, inline fuse holder and relay handle the compressor circuit. The fill-rate figures are quoted at a 13.8 V supply, which is roughly what a charging vehicle system delivers. With the engine off, expect slower refills. That is our editorial inference, not a HornBlasters figure.
Mounting is the main constraint. The horn needs a flat, sturdy spot about 17 x 15 x 11 in. HornBlasters tags the kit for full-size and mid-size pickups and SUVs. The M3 air source has to stand upright and stay enclosed. In practice, that means inside a cab, under a rear seat, in a sealed toolbox, or in a covered cargo area, not on a frame rail. Keep it clear of heat and exhaust. Our compressor mounting guide covers placement trade-offs.
- Run the 1/4 in. air line from the M3 outlet to the pre-installed valve on the horn, and keep bends gentle.
- Use the included relay and toggle switch for the compressor, and fuse close to the battery.
- Drain moisture from the tank regularly. Our tank draining guide explains why.
- Check your state’s rules before use on public roads. Start with are train horns legal on cars.
HornBlasters says installation is covered by the included instructions, and it publishes wiring diagrams on its manuals page. If you’d rather hire a shop, see our train horn install cost guide. For a step-by-step DIY walkthrough, see how to install a train horn.
Sources
- HornBlasters — Rhino Black 3 Liter Train Horn Kit (HK-Q3-M3) — kit price ($399.99, compare-at $529.97), 120/90 PSI, 2-3 s honk, 35 s recharge, 2 min full fill at 13.8 V, 18 A, horn and air source dimensions, 14.2 lb horn weight, included items, mounting and compressor-detachment warranty conditions, 2-year warranty, vehicle tags, on-page 5.0 rating across 77 reviews, product photos
- HornBlasters — Rhino Train Horn (AH-Q3, horn only) — $249.99 horn-only price, 150 PSI max pressure, 12/24 V valve, standalone includes, 1-year horn warranty, alternate metric dimensions
- HornBlasters — Mini Outlaw 3 Liter Horn Kit — $369.99 price for the alternative using the same M3 air source
- HornBlasters — Mini Outlaw 127H Train Horn Kit — $399.99 weather-resistant alternative, 1.5-gallon tank, 4-5 s honk
- HornBlasters — Decibels explained: why fake ratings mislead buyers — the brand’s position on not publishing dB figures
- HornBlasters — Instructions, manuals and wiring diagrams — install documentation availability
- Kleinn — Model HK3 ProBlaster Chrome Triple Air Horn Kit — $439.95 price, 130 PSI system for the alternative
- Big Rig Chrome Shop — Rhino Black 3-Liter Horn Kit — $400.99 retail cross-check; outdated 110/85 PSI spec copy
- eBay — HornBlasters HK-Q3-M3 Rhino M3 Black 3 Liter Train Horn Kit — part number cross-check and secondary-market availability
- Torque Supply Co — Rhino 3 Liter Horn Kit — second reseller listing still carrying older 110 PSI copy
Train Horn Hub aggregates publicly available data. We do not test products in-house. All trademarks belong to their respective owners.
The Rhino 3 Liter kit is a good-value, complete way to get HornBlasters' full-size three-chime Rhino horn on a pickup or SUV for occasional short blasts, provided you can mount the air source inside the vehicle. If you need longer honks or an under-body air system, step up to a sealed kit such as the Mini Outlaw 127H.
Frequently asked questions
Quick answers to the questions people ask most about this topic.
- How loud is the HornBlasters Rhino 3 Liter kit?
- HornBlasters doesn't publish a decibel rating, test distance or chord frequencies for the Rhino, and it has a public page arguing that many dB claims mislead buyers. The kit runs the three-chime Rhino horn at 120 PSI and ships with earplugs. It is clearly loud, but its output isn't quantified on paper.
- How long can the Rhino 3 Liter kit honk?
- HornBlasters quotes 2-3 seconds of honk time from the M3 3-liter tank. Recovering from 90 to 120 PSI takes about 35 seconds (± 5 sec.) at 13.8 V, and a full fill from empty takes about 2 minutes.
- Can I mount the Rhino 3 Liter air source under my truck?
- Not without risking the warranty. HornBlasters says the tank-mounted compressor isn't fully sealed and must be mounted upright in an enclosed space away from moisture and dirt. Detaching the compressor from the tank also voids the warranty. For under-body mounting, look at a weather-resistant kit such as the Mini Outlaw 127H.
- Is it 110 PSI or 120 PSI?
- HornBlasters' current product page lists 120 PSI operating and 90 PSI restart pressure. Some retailer listings still carry older copy showing 110 PSI and 85 PSI. We use the manufacturer's current figures.
- What warranty does the Rhino 3 Liter kit have?
- The kit components carry a 2-year manufacturer's defect warranty, plus HornBlasters' 30-day satisfaction guarantee (a 15% restocking fee may apply on returns). Improper mounting, detaching the compressor, or physical damage voids coverage.
