If you’re comparing the Bunker Airtight Stash Jar against the Keefer Onyx™ Stash Jar, you’re weighing two very different approaches to the same problem: keeping your herb fresh, sealed, and out of sight. One leans on stainless steel and steel-can toughness. The other is built around UV-blocking glass and a lab-grade seal. Here’s how they actually compare.
Note: Keefer is not affiliated with Blue Bus Fine Tools, the maker of the Bunker Airtight Stash Jar. This comparison is based on publicly available product specifications.
Quick Comparison
| Feature | Bunker Airtight Stash Jar | Keefer Onyx™ Stash Jar |
|---|---|---|
| Material | 304 food-grade stainless steel | UV-blocking borosilicate glass |
| Seal type | Rubber/silicone gasket | Lab-grade hermetic silicone gasket |
| UV protection | Opaque metal body (blocks light by default) | Purpose-engineered UV-blocking glass, fully opaque |
| Capacity | 160ml, 265ml, or 500ml (three sizes) | Half ounce / 14g (single size) |
| Included extras | Reusable moisture bag | — |
| Color options | Light blue, silver, black | Matte onyx black |
| Price | ~$17–$35 depending on size and retailer | $26.99 |
Material & Build Quality
The Bunker is built from 304 food-grade stainless steel, which makes it genuinely tough — the kind of container you can toss in a bag without worrying about it cracking. Steel is also naturally opaque, so it blocks light without needing any special glass treatment.
The Keefer Onyx™ Stash Jar takes a different route: it’s built around UV-blocking borosilicate glass rather than metal. Borosilicate is more shatter-resistant than standard glass, and unlike steel, it lets the jar stay lightweight while still fully blocking light exposure. If your priority is maximum drop resistance in something like a backpack that gets thrown around daily, steel has an edge. If you want a container that feels premium and doesn’t scratch or dent with normal use, glass wins.
Smell-Proof & Seal Performance
Both jars use a silicone-based gasket to lock in odor, but the engineering behind that seal differs. Bunker uses a rubber/silicone seal on a screw-top or magnetic-close lid depending on size. The Onyx uses a lab-grade hermetic silicone gasket specifically designed to hold its seal integrity through thousands of open-close cycles — a common failure point on rubber-lined metal lids, which tend to lose their tight seal within a couple months of daily use.
For occasional or light use, either jar will keep odor contained. For daily users who are opening their jar multiple times a day, seal durability over time becomes the more relevant factor.
UV & Freshness Protection
This is where the two products solve the same problem differently. Bunker’s stainless steel body blocks UV simply because metal is opaque — there’s no light getting through, period. The Onyx™ uses glass that’s specifically engineered to block UV wavelengths while still being glass, which is why it’s marketed as UV-blocking rather than just “opaque.” Functionally, both approaches stop light-driven degradation of cannabinoids and terpenes. The practical difference comes down to material preference: some people want to be able to glance at their jar and immediately know what’s inside without opening it (which requires at least partial transparency and isn’t really an option with either of these fully opaque products), while others prioritize a premium glass feel over steel.
Capacity & Sizing Options
Bunker offers more flexibility here — it comes in 160ml, 265ml, and 500ml sizes, so you can size up or down depending on how much you’re storing. The Onyx™ is purpose-built around a single half-ounce (14g) capacity, which is sized specifically to match the most common dispensary purchase quantity. If you regularly buy in bulk or want one container for a larger stash, Bunker’s larger size options may fit better. If you’re storing a standard half-ounce purchase and want a container sized exactly for that without wasted headspace (which matters for minimizing oxygen exposure), the Onyx™ is built around that use case specifically.
Price & Value
Bunker’s pricing varies by size and retailer, generally starting in the high teens for the smallest size and increasing for the 265ml and 500ml options. The Onyx™ is priced at a flat $26.99 regardless of size, since it only comes in one capacity. If you’re comparing cost per use, factor in the moisture bag Bunker includes, versus the glass build and hermetic seal engineering you’re paying for with the Onyx™.
Who Should Buy Which?
- Choose the Bunker if you want maximum drop/impact durability, multiple size options, and a moisture bag included out of the box.
- Choose the Keefer Onyx™ if you want a premium glass container sized specifically for a half-ounce, engineered for long-term seal reliability, and don’t need multiple capacity options.
For a broader look at how these two stack up against other storage formats entirely, see our full weed storage container buyer’s guide or our breakdown of glass stash jars vs. mason jars.
Frequently Asked Questions
Is the Bunker Airtight Stash Jar actually smell-proof?
Bunker uses a rubber/silicone gasket designed to seal in odor, and steel bodies generally hold a tight seal well when new. Seal performance on any gasket-based container can degrade with heavy daily use over time.
Does the Keefer Onyx™ Stash Jar come in different sizes?
No — the Onyx™ is purpose-built as a single half-ounce (14g) capacity jar, sized to match a standard dispensary purchase.
Which is more durable, glass or steel?
Stainless steel generally holds up better against hard drops and impacts. The Onyx™ uses borosilicate glass, which is more shatter-resistant than standard glass but isn’t as impact-proof as steel.
Do both jars block UV light?
Yes. Bunker’s stainless steel body is naturally opaque and blocks all light. The Keefer Onyx™ uses glass specifically engineered to block UV wavelengths while remaining fully opaque.
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