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Mizu M8 with Stainless Steel Cap

Mizu M8 with Stainless Steel Cap

Recommended

Single-wall 18/8 steel bottle paired with Mizu's all-stainless screw cap, so the water path is steel plus a small silicone gasket.

The verdict: Silicone only

The M8 is a single-wall 18/8 stainless bottle. It ships with a plastic loop cap, but Mizu sells a dedicated all-stainless M-series Steel Cap, and with that cap the water path is 18/8 steel sealed by a small removable silicone gasket - nothing plastic touches the drink. We rate it in that steel-cap configuration; with the stock plastic loop cap it would be minimal-contact. An affordable, widely-sold alternative to the Klean Kanteen / Hydro Flask steel-cap route.

Verification: Manufacturer confirmed · Last reviewed July 2026

Requires an upgrade to reach the silicone only rating — you also buy:
Stainless Steel Cap (M-series) · $ Mizu →

The M8 ships with a plastic loop cap; this all-stainless M-series cap is what makes the water path plastic-bar-the-gasket. Buy it separately.

What it's made of

PartMaterialWater contact
bottle body (single-wall)
18/8 (304) food-grade stainless; some finishes add an exterior powder coat that does not contact the drink
Stainless Steel
304 / 18-8
Yes primary
Loop cap (stock - replaced by the Steel Cap) ships with — replace
Plastic loop cap the M8 ships with.
Polypropylene
PP, #5
primary
Steel Cap (add-on - replaces the stock plastic loop cap)
Mizu's all-18/8-stainless M-series cap; a separate SKU.
Stainless Steel
304 / 18-8
Yes primary
cap gasket
small removable silicone sealing gasket - the only non-metal part in the water path
Silicone Yes seal

Mizu's M8 is a lightweight single-wall narrow-mouth 25oz stainless bottle - no insulation, so it's lighter and cheaper than a double-wall bottle. The all-steel M-series cap it takes fits every M-series body (M5, M8), so one cap covers the range. It's the affordable end of the "steel body + steel cap" route that Klean Kanteen and Hydro Flask also sell.

Pros

  • Among the cheapest ways into an all-steel drink path
  • One cap fits the whole M-series line (M5, M8)
  • Light single-wall body; the silicone gasket is small and removable

Cons

  • Doesn't ship this way - the all-stainless cap is a separate purchase
  • Single-wall, so no insulation
  • Some finishes use an exterior powder coat (doesn't touch the drink, but worth noting)
  • The all-steel cap has been intermittently backordered

Notes

Common questions

Does the Mizu M8 with Stainless Steel Cap have plastic in it?

No petroleum plastic touches your water. On the Mizu M8 with Stainless Steel Cap, the cap gasket is silicone, and the rest of the water path is stainless steel.

What is the Mizu M8 with Stainless Steel Cap made of?

Part by part, the Mizu M8 with Stainless Steel Cap is: bottle body (single-wall) — stainless steel; Steel Cap (add-on - replaces the stock plastic loop cap) — stainless steel; cap gasket — silicone.

Does the Mizu M8 with Stainless Steel Cap have silicone in it?

Yes — the cap gasket is silicone on the Mizu M8 with Stainless Steel Cap. It is a seal rather than a surface your water sits against, which is stainless steel.

Is the Mizu M8 with Stainless Steel Cap BPA-free?

No plastic touches your water on the Mizu M8 with Stainless Steel Cap — the water path is stainless steel and silicone — so BPA, which comes from polycarbonate and epoxy plastics, is not in play here.

Where is the Mizu M8 with Stainless Steel Cap made?

The Mizu M8 with Stainless Steel Cap is made in China.

Categories: Water Bottles

Sources

Every material claim above is backed by these. This is the scattered info we centralized.

Spot a mistake or something out of date? Let us know — corrections are how this stays accurate.