Stainless steel lunch box
Stainless Steel Lunch Box 3-Pack — 27 oz (800 ml)
The SEIDO Cookware stainless steel lunch box 3-pack contains three identical 27 oz (800 ml) containers with lids, each made from 304 (18/8) food-grade stainless steel. They are microwave-safe by design, made without intentionally added PFAS and without synthetic coatings, and covered by a 5-Year Warranty. Sold in the US on Amazon.
- 27 oz (800 ml) × 3
- Microwave-safe
- Dishwasher-safe
- 5-Year Warranty
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Each container holds one complete adult lunch, so a single batch-cooking session fills three days — office, gym, or commute. Stainless steel resists staining and odor retention, and it is built to be kept. See price on Amazon.
The material
Steel, not plastic.
100% 304 (18/8) food-grade stainless steel, made without intentionally added PFAS. It does not stain from tomato sauce, hold onto yesterday's curry, or go cloudy in the wash the way plastic does.
See what it is made of
Designed for the microwave
Steel you can microwave.
Everyone knows you do not put metal in a microwave — which is why this one was engineered for it rather than sold with a warning. It is the single question people ask most about stainless steel containers, so we answered it in full.
Can you microwave stainless steel? →Designed for the microwave
Many stainless steel food containers carry the same warning: do not microwave. This 3-pack is the deliberate exception. Each 27 oz (800 ml) container is engineered to be microwave-safe, so a packed meal goes from refrigerator to microwave with no transfer to another dish.
That capability is designed into the construction itself: these containers are engineered for reheating in a household microwave. It is the feature that changes how the product gets used. A microwave safe stainless steel lunch box means lunch is packed cold in the morning and eaten hot at noon — no second dish, no compromise container.
If you were taught that metal and microwaves never mix, the engineering behind this is worth five minutes. We explain exactly how a stainless steel container can be microwave-safe — and why many are not — in our Learn article on microwave-safe stainless steel.
Why a 3-pack?
Meal prep runs on a simple rhythm: cook once, eat three times. One pot of chili, curry, or grains on Sunday evening becomes Monday, Tuesday, and Wednesday's lunches — portioned, lidded, and lined up in the refrigerator before the week begins.
Three identical containers keep that rhythm honest. Every portion is the same 27 oz (800 ml), so a batch divides cleanly into three equal meals — no hunting through a drawer of mismatched plastic.
The 27 oz (800 ml) capacity is deliberate. It holds one complete adult lunch — a full grain bowl, a proper pasta portion, or a salad with protein — so one container equals one meal. Three containers, three days, one cooking session.
Built for the office, the gym, and the commute
At the office, the workflow is the whole point: take the container from the refrigerator, heat it in the office kitchen microwave, eat well at your desk or away from it. Because the container itself is microwave-safe, there is no scraping your lunch into a communal bowl first.
For the gym, a pre-portioned meal rides in the bag and is ready the moment training ends. 27 oz (800 ml) is sized for a real meal rather than a snack, and stainless steel resists picking up the smell of whatever it carried yesterday.
For the commute, steel earns its place. A stainless steel container takes the knocks of a daily bag and resists the cracking, clouding, and warping that wear plastic out over time. Pack it, carry it, heat it, wash it with dish soap — and repeat, backed by a 5-Year Warranty.
Why stainless steel for a lunch box?
Stainless steel resists staining. Tomato sauce, curry, turmeric — the non-porous surface of 304 (18/8) stainless steel resists absorbing the colors and odors that stain plastic containers.
It resists holding odors too. The steel resists holding on to yesterday's salmon or garlic — wash with hot water and dish soap, and the container is ready for whatever comes next. There is no synthetic lining to trap smells, scratch, or flake: these containers are made without intentionally added PFAS and without synthetic coatings.
And it is built to be kept. There is no coating to wear out or flake away with ordinary daily use. That durability is why every 3-pack carries a 5-Year Warranty.
Specs at a glance
The stainless steel lunch containers set at a glance:
- Three identical containers, each with its own lid
- Capacity: 27 oz (800 ml) each
- Material: 304 (18/8) food-grade stainless steel
- Microwave-safe by design
- Made without intentionally added PFAS; without synthetic coatings
- Sized for adult meal prep — office, gym, commute
- 5-Year Warranty
- Sold in the US on Amazon — See price on Amazon
Verified, not claimed.
100% 304 (18/8) food-grade stainless steel, made without intentionally added PFAS. The third-party test documents are published for you to read.
The detail
Specifications
| Capacity | 27 oz (800 ml) each |
|---|---|
| Set | 3 containers with lids |
| Material | 100% 304 (18/8) food-grade stainless steel |
| Microwave | Microwave-safe — engineered for it, SGS tested |
| Dishwasher | Dishwasher-safe — SGS tested, EN 12875-1, 50 cycles |
| Oven | Container oven-safe without the lid — SGS tested |
| Freezer | Refrigerator and freezer safe — SGS tested |
| Warranty | 5-Year Warranty |
Care and technique
Uncoated steel rewards a little technique, and the technique is quick to learn. These cover it:
Buying and returns
SEIDO Cookware sells through Amazon, so your order, delivery and returns are handled under Amazon’s own policy — including their returns window. We do not take payment on this site, which is also why you will not find a price here: Amazon’s is the one that counts.
Our 5-Year Warranty applies wherever you bought it.
Frequently asked questions
Can these stainless steel lunch boxes go in the microwave?
Yes. Each container in the SEIDO Cookware stainless steel lunch box 3-pack is microwave-safe by design. The construction is engineered specifically for microwave reheating — that sets these apart from the many stainless steel containers that carry a do-not-microwave warning. Reheat a packed lunch straight from the refrigerator in the office kitchen.
What fits in a 27 oz (800 ml) stainless steel container?
27 oz (800 ml) holds a complete adult lunch in one container: a grain bowl with roasted vegetables and chicken, a full pasta portion, a salad with protein on top, or leftovers from last night's dinner — rice, curry, stir-fry, chili. It is sized for one substantial meal rather than a snack, which is why three containers cover three full days of packed lunches.
Is this one lunch box or three separate containers?
It is three separate, identical containers, each with its own lid. Every container holds 27 oz (800 ml) and is made from 304 (18/8) food-grade stainless steel. Because the three are identical, every portion you pack is the same size. The 3-pack is built around a batch-cooking rhythm: cook once, portion three meals, and have a container ready for each day.
What are the lunch box containers made of?
Each container is made from 304 (18/8) food-grade stainless steel. The containers are made without intentionally added PFAS and without synthetic coatings. There is no lining to scratch, stain, or flake; the surface your food touches is the steel itself.
What warranty do the lunch boxes carry?
Every SEIDO Cookware stainless steel lunch box 3-pack is covered by a 5-Year Warranty. Stainless steel is the reason we can offer it: 304 (18/8) stainless has no coating to wear away or degrade with normal use. The 3-pack is sold in the US on Amazon — see price on Amazon.
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