# Inflatable Life Jacket Rearm Kits (2026): Matching the Kit, Checking the Cylinder, and When to Replace It

> Which rearm kit fits which Onyx and Mustang inflatable, what the Coast Guard means by serviceable, and the bobbin and cylinder checks the makers ask for.

- Source: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits
- Publisher: SaltProofLab (https://saltprooflab.com)
- Published: 2026-09-29
- Category: life-jackets-safety
- Tags: rearm kit, inflatable life jacket, CO2 cylinder, Onyx rearming kit, Mustang re-arm kit, life jacket maintenance
- Method: picks chosen from Amazon listings and brand specs; not hands-on tested; current Amazon prices are on the page; content checked 2026-09-29.
- Quick answer: Buy the kit printed on your jacket's label, from the jacket's maker, and keep a spare aboard. For Onyx inflatables, Amazon.com sells the M-16, M-24 In-Sight, A-33 In-Sight and A/M-33 All Clear kits; the A/M-24 All Clear kit and every Mustang kit were third-party only.

## Key takeaways

- The Coast Guard says an inflatable without a full cylinder and all-green status indicators is not serviceable and does not count as a life jacket aboard.
- Onyx's bobbins carry a date code and a three- or five-year shelf life; Onyx says to replace them yearly in humid regions like the Southeast.
- The number in an Onyx or Mustang model name is the cylinder size in grams, but the thread or bayonet fitting has to match too.

## Products (chosen from listings, not tested)

1. **Onyx M-16 Rearming Kit, 16 Gram** (details: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B013FWYS34) — Buy it if you wear the M-16 belt pack; buy two if you plan a practice pull.
   - Pros: Fits the Onyx M-16 Manual Inflatable Belt Pack (model 1309), per the listing; 16 g CO2 cylinder with a 3/8 in thread and a green Halkey-Roberts indicator tab, per Onyx
   - Cons: Manual kit with no bobbin; it fits no other Onyx jacket
2. **Onyx M-24 In-Sight Rearming Kit, 24 Gram** (details: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B005KKWTVI) — Buy it if your jacket's label says M-24 In-Sight and names kit 1354.
   - Pros: Listed for Onyx manual In-Sight inflatable life jackets; 24 g CO2 cylinder on a Halkey-Roberts bayonet assembly, per Onyx (kit model 1354)
   - Cons: The listing has no bullet points; confirm the kit number on your jacket first
3. **Onyx A-33 In-Sight Rearming Kit** (details: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B00NXVV80O) — Buy it if you wear the A-33 In-Sight and want the bobbin and cylinder replaced together.
   - Pros: Fits A-33 In-Sight automatic/manual inflatable life jackets, per the listing; 33 g CO2 cylinder with a Halkey-Roberts bayonet assembly plus a water-soluble bobbin
   - Cons: Bayonet fitting; it will not fit the threaded A/M-33 All Clear
4. **Onyx A/M-33 All Clear Rearming Kit** (details: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B07X374SGR) — Buy it if your jacket is the All Clear model with the clear inflator cover.
   - Pros: Fits A/M-33 All Clear automatic/manual inflatable life jackets, per the listing; 33 g CO2 cylinder with a 1/2 in thread and a water-soluble bobbin
   - Cons: Threaded fitting; not interchangeable with the bayonet-style A-33 In-Sight kit

A fired inflatable is a deflated bag until you rearm it, and the kit that does it is specific to the jacket. Most confusion comes from two numbers that look alike: the cylinder size in grams and the maker's kit number. Match the kit number printed on the jacket; the gram size alone is not enough.

**How we chose:** we did not test these kits. We matched each one to Onyx's and Mustang Survival's published kit lists and kept only kits sold by Amazon.com or the maker and in stock on September 29, 2026.

## Onyx kits sold by Amazon.com

| Kit | Onyx kit model | Cylinder and fitting | Bobbin included | Fits (per listing or Onyx) | Sold by | Amazon price |
|---|---|---|---|---|---|---|
| [Onyx M-16](https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B013FWYS34) | 1370 | 16 g, 3/8 in thread | No (manual) | M-16 belt pack, model 1309 | Amazon.com | see the current Amazon price on the page |
| [Onyx M-24 In-Sight](https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B005KKWTVI) | 1354 | 24 g, bayonet | No (manual) | Manual In-Sight jackets | Amazon.com | see the current Amazon price on the page |
| [Onyx A-33 In-Sight](https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B00NXVV80O) | 1362 | 33 g, bayonet | Yes | A-33 In-Sight auto/manual | Amazon.com | see the current Amazon price on the page |
| [Onyx A/M-33 All Clear](https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits#product-B07X374SGR) | 1363 | 33 g, 1/2 in thread | Yes | A/M-33 All Clear auto/manual | Amazon.com | see the current Amazon price on the page |

Kit models, fittings and contents come from Onyx's product pages for the [M-16](https://www.onyxoutdoor.com/products/m-16-rearming-kit), [M-24 In-Sight](https://www.onyxoutdoor.com/products/m-24-in-sight-kit-rearming-kit), [A-33 In-Sight](https://www.onyxoutdoor.com/products/a-33-in-sight-kit-rearming-kit) and [A/M-33 All Clear](https://www.onyxoutdoor.com/products/a-m-33-all-clear-rearming-kit) kits.

## Why the gram size is not enough

Onyx's [rearming kits page](https://www.onyxoutdoor.com/pages/rearming-kits) decodes its model names: the letter is the inflation style (manual, automatic, or automatic/manual) and the number is the CO2 cylinder weight in grams. So an A-33 In-Sight and an A/M-33 All Clear both take 33 g.

They still take different kits. Onyx lists the In-Sight cylinder on a Halkey-Roberts bayonet assembly and the All Clear cylinder with a 1/2 in thread. A kit with the right gas and the wrong fitting will not arm the jacket.

Onyx's [FAQ](https://www.onyxoutdoor.com/pages/faqs) is blunt about substitutes: use a rearm kit with a cylinder "supplied by the maker of the vest." It says the correct cylinder is shown on the jacket and in the owner's manual, or you can get it by calling the maker. That is why generic 24 g and 33 g cylinders sold on Amazon are not listed here.


## Mustang Survival's kit letters

Mustang names its kits by letter, and its [re-arm kit collection](https://www.mustangsurvival.com/collections/re-arm-kits) lists which jackets each one fits. The kits an angler is most likely to need:

| Mustang kit | Cylinder | Fits, per Mustang |
|---|---|---|
| Kit D | 24 g auto/manual, bayonet | MIT 100 manual and automatic; Fluid belt pack |
| Kit L | 24 g auto/manual, threaded | MIT 100 Convertible A/M |
| Kit E | 33 g auto/manual, bayonet | 1F Automatic and 3F Manual |
| Kit H | 17 g auto/manual | MIT 70 (MD4031, MD201403, MD2014C3, MD201503, MD2015C3) |
| Kit K | 17 g auto/manual | MIT 70 (MD4041, MD4042) |
| Kit J | 16 g manual | Minimalist and Essentialist belt packs |

The same page lists Kits A, B and C for Mustang's auto-hydrostatic jackets, including the Elite 38 and EP 38. On Amazon we found Kits B, D, E, I, K, L and O, all from third-party sellers such as ScubaDotCom and Harvard Marine, so none is linked here.

## What "serviceable" means

The Coast Guard's [federal requirements guide](https://www.uscgboating.org/assets/1/AssetManager/Boaters-Guide-to-Federal-Requirements-for-Receational-Boats-20231108.pdf) gives two conditions for an inflatable: "They must have a full cylinder" and "All status indicators must be green."

Its [life jacket page](https://uscgboating.org/recreational-boaters/life-jacket-wear-wearing-your-life-jacket.php) spells out the consequence: without both, the jacket "is NOT serviceable, and does NOT satisfy the requirement to carry lifejackets." The same page says inflatables should be maintained per the manufacturer's instructions, and that they are not appropriate for weak or non-swimmers.

**Key point:** a fired jacket with no spare kit aboard leaves that person without a legal life jacket for the rest of the trip.

## Checking the cylinder and bobbin

Onyx's FAQ asks for three routine checks:

- **The cylinder.** Unscrew it and look at the seal to be sure it has not been broken or pierced. A punctured cylinder cannot be reused, so check that it is full before each outing. On jackets with a cylinder seal indicator, green means full and red means replace.
- **The bobbin.** Check the yellow water-sensing bobbin before each use. Onyx bobbins carry a date code and a three- or five-year shelf life depending on the jacket, and should be replaced yearly in humid regions like the Southeast.
- **The automatic system.** Onyx says the Coast Guard recommends testing it in water at the start of each season.

Onyx's A-33 and A/M-33 listings add that the Coast Guard recommends buying an extra kit to try out your jacket and learn how it works. That test uses up a cylinder, which is one more reason to own two kits.

## Rearming, step by step

Follow your own jacket's manual; the steps below are Onyx's for its automatic jackets, from the FAQ. Let all the air out through the oral tube first. Remove the used cylinder and discard it, then remove the clear cap and the used yellow bobbin.

Check that the housing is dry and clean. Fit the new bobbin with its slots on the housing ridges, screw the cap back on, confirm the new cylinder is not pierced, and screw it in firmly. The service indicator should show green; if it shows red, start again. Repack with the yellow pull tab hanging outside.

Onyx also warns against fully inflating a jacket by mouth and then firing the CO2: done repeatedly, it "will damage the PFD to the point that it will not hold air or float." Never use a pump or air compressor.


## When the jacket, not the kit, needs replacing

No maker we read gives a fixed lifespan for an inflatable. Onyx's warning about oral-then-CO2 inflation is the clearest sign of wear to watch for: a chamber that no longer holds air. If yours won't stay firm, or the indicators won't turn green with a new kit, stop using it and contact the maker.

A foam jacket needs none of this, which is why it is often the better choice for guests, kids and kayak fishing. Our [inflatable vs foam life jackets guide](https://saltprooflab.com/life-jackets-safety/inflatable-vs-foam-life-jackets) covers who should wear which, and the Onyx A/M-24 and M-16 jackets these kits serve.

Related: the [USCG equipment checklist by boat length](https://saltprooflab.com/life-jackets-safety/uscg-required-safety-equipment), [kill switch lanyards](https://saltprooflab.com/life-jackets-safety/kill-switch-lanyards-ecos-rule) that clip to the jacket, and [personal locator beacons](https://saltprooflab.com/life-jackets-safety/personal-locator-beacons).

## Kits we could not link

Onyx's current A/M-24 kit is the [A/M-24 All Clear kit](https://www.onyxoutdoor.com/products/a-m-24-all-clear-rearming-kit) (model 1357, a 24 g cylinder with a 1/2 in thread and a bobbin). On Amazon it was sold only by a third-party distributor, as was the older kit #1352 that the A/M-24 listing names. Check your jacket's label to see which one it takes.

We found no rearm kit sold under Stearns' name on Amazon, and Stearns' [support page](https://www.stearnsflotation.com/support?cfid=faq) publishes no kit chart; call Stearns with your model number. The Maximum Inflation 33 g kit Amazon.com sells is a generic replacement, not a jacket maker's own kit, so we left it out.

We found no recalls of Onyx, Mustang Survival or Stearns products since 2023 in the [CPSC recall database](https://www.cpsc.gov/Recalls); our [recall page](https://saltprooflab.com/recalls) tracks marine recalls.

## Frequently Asked Questions

### Can I use a 24 g cylinder from another brand if the thread matches?

Onyx says no: its FAQ says to use a kit with a cylinder supplied by the jacket's maker, because many CO2 cylinders are sold for other uses. The right one is printed on the jacket and in its manual.

### Do I need a new bobbin if I fire a manual-only jacket?

No. Manual kits such as Onyx's M-16 and M-24 In-Sight contain only a cylinder (and, for the M-16, an indicator tab), per Onyx. Automatic kits add the water-soluble bobbin because the automatic mechanism dissolves it when it fires.

### Where is the kit number on the jacket?

On the jacket's label and in its owner's manual, per Onyx. Onyx's [rearming page](https://www.onyxoutdoor.com/pages/rearming-kits) also links a rearming video for each of its styles, from the M-16 belt pack to the A/M-33 All Clear.

### Can I switch an auto/manual jacket to manual-only?

Onyx's FAQ describes it for its convertible jackets: remove the cylinder, cap and bobbin, fit the yellow "Manual" cap, and reinstall the cylinder, leaving the warning flag visible. Only do this if your jacket's manual allows it.

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*SaltProofLab is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.*

## Sources

- onyxoutdoor.com: [M-16](https://www.onyxoutdoor.com/products/m-16-rearming-kit)
- onyxoutdoor.com: [M-24 In-Sight](https://www.onyxoutdoor.com/products/m-24-in-sight-kit-rearming-kit)
- onyxoutdoor.com: [A-33 In-Sight](https://www.onyxoutdoor.com/products/a-33-in-sight-kit-rearming-kit)
- onyxoutdoor.com: [A/M-33 All Clear](https://www.onyxoutdoor.com/products/a-m-33-all-clear-rearming-kit)
- onyxoutdoor.com: [Rearming kits](https://www.onyxoutdoor.com/pages/rearming-kits)
- onyxoutdoor.com: [FAQ](https://www.onyxoutdoor.com/pages/faqs)
- mustangsurvival.com: [Re-arm kit collection](https://www.mustangsurvival.com/collections/re-arm-kits)
- U.S. Coast Guard Boating Safety: [Federal requirements guide](https://www.uscgboating.org/assets/1/AssetManager/Boaters-Guide-to-Federal-Requirements-for-Receational-Boats-20231108.pdf)
- U.S. Coast Guard Boating Safety: [Life jacket wear wearing your life jacket.php](https://uscgboating.org/recreational-boaters/life-jacket-wear-wearing-your-life-jacket.php)
- onyxoutdoor.com: [A/M-24 All Clear kit](https://www.onyxoutdoor.com/products/a-m-24-all-clear-rearming-kit)
- stearnsflotation.com: [Support page](https://www.stearnsflotation.com/support?cfid=faq)
- U.S. Consumer Product Safety Commission: [CPSC recall database](https://www.cpsc.gov/Recalls)

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Last updated: 2026-09-29
Canonical URL: https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits
How to cite: "Inflatable Life Jacket Rearm Kits (2026): Matching the Kit, Checking the Cylinder, and When to Replace It", SaltProofLab, https://saltprooflab.com/life-jackets-safety/inflatable-life-jacket-rearm-kits (checked 2026-09-29).
Disclosure: as an Amazon Associate SaltProofLab earns from qualifying purchases. Safety information summarizes public guidance and is not medical advice.