Optimus Gemini II review

This is a source-based assessment of the Optimus Gemini II, item 8021584 / EAN 0604375215849. It is a different, newer exact identity from the recalled Optimus Gemini item 8020872. The manufacturer’s current page is an inquiry page, not evidence of a live US retail offer. No hands-on testing, ownership or independent boil-time measurement is claimed.

Two burners change the cooking scale

The Gemini II is a fold-flat remote-canister stove with two independently controlled burners, an integrated wind shield and a low frame. Its main distinction from a compact backpacking burner is simultaneous cooking: a pot can simmer while another heats, without claiming a particular number of diners or a particular meal size. Manufacturer copy describes boiling, simmering and searing on both burners; adjustable output is documented, not independently tested.

Optimus lists 760 g without accessories. The fact sheet separately lists a canister stand and transport bag as accessories, so 760 g is not the complete supplied kit or fueled carry weight. Packed size is 305 × 70 × 105 mm; in-use dimensions are 385 × 195 × 105 mm. Its low-profile frame may be more stable than a narrow top-mounted burner, but the manual still requires a horizontal, level surface and sets cookware limits. A fold-flat shape is a packing advantage, not a claim that the full system is ultralight.

Match the manual’s cartridge instructions

The English manual describes a butane/isobutane/propane mixture and says to use Optimus EN 417 cartridges. It lists 100, 110, 220, 230 and 450 g cartridge sizes and warns that attempting other cartridge types may be hazardous. The blend recipe is not specified as MSR 80/20 or Jetboil JetPower, so a threaded fit or general resemblance is not enough to satisfy either brand-specific fuel choice in the finder. Check the label and the complete instructions for the exact stove and cartridge.

The current fact sheet gives 4.6 kW nominal under EN 521 and 17,000 BTU/h under EN 417; the product page also describes two 4,600 W burners. The units/conditions are not a single interchangeable output rating. The fact sheet reports about four minutes for one liter of water and up to 165 minutes from a 450 g cartridge while using one burner. These remain manufacturer figures; the duration does not promise the same result with both flames running, and conditions such as wind and cookware matter.

Use its limits rather than a wider-pan guess

The English manual caps cookware at 23 cm (9 in) and says pan plus food must not exceed 4 kg on each burner side. A vessel within those limits still needs to sit securely on the supports, and the two supports do not create an unlimited one-piece griddle surface. The wind protection is built into the stove. The documentation reviewed here does not authorize an additional separate windscreen; an integrated shield is not the same as permission to wrap the stove or canister in an extra barrier. The canister must remain upright and outside dangerous heat.

For cooking technique, the two separate controls offer more flexibility than a single flame, although the manufacturer’s simmer claim is not a measured minimum-flame result. The wide footprint and 760 g body-only figure are the price of carrying two burners; for a solo boil-and-eat menu, a smaller one-burner arrangement may be the more proportionate comparison.

Recall identity matters

Katadyn’s official 2022 recall notice names the earlier Optimus Gemini, item 8020872, EAN/GTIN 0604375208728, and specified serial numbers. The Gemini II page identifies item 8021584 and GTIN 0604375215849. Those are distinct identifiers, so the earlier notice should not be silently transferred to the Gemini II; equally, this comparison is not a guarantee against later notices or a substitute for checking the specific unit. Before buying, confirm item number 8021584, the included accessories and a matching instruction sheet. The inquiry-only product page establishes neither an exact seller package nor current availability.