WISPR 2

The WISPR 2 carries no battery: a butane catalytic burner behind the grid brings its stainless filling chamber to roughly 210 °C in thirty seconds. That chamber threads straight into the body and takes the brunt of the residue, while the flexible silicone straw above it catches the condensate. IOLITE sells the chamber, its mesh and the mouthpiece as consumables, which tells you what needs attention first.

1. Let it go cold: IOLITE will not have you touch any of this until the unit has fully cooled. The catalytic reaction continues briefly after the gas is shut off, and the Ultem casing holds that warmth.

2. Take the top apart: Draw the silicone straw mouthpiece and the filling chamber off the body, part the two, then pull the straw tip off the end. One of the two supplied pipe cleaners goes through the bore of the straw.

3. Coax a stuck chamber out: The filling chamber can end up gripped inside the body. Thread the supplied removal tool into it and work it free that way instead of levering at the rim.

4. Free the screen and its C clip: The mesh seats in the narrow end of the chamber behind a C clip, which IOLITE sells as a retaining ring with its spare screens. Feed the thin tip of the screen removal tool in through that narrow end and go carefully, as both pieces can spring loose.

5. Wash the loose parts: IOLITE puts the straw mouthpiece, its tip, the filling chamber and the mesh screen through a dishwasher, though pieces this small need thought about where they sit in the rack. Nothing else on the WISPR 2 should meet water.

6. Refit the mesh facing outward: Set the screen back in the chamber with the mesh outward, press it home with the thick end of the screen removal tool, then squeeze the C clip in behind it. If fine debris is getting through to your mouth, the double woven fine screens are the alternative to the seven dot pattern.

7. Leave the burner sealed: The catalytic heater, the heat pin and the gas valve are built into the body and accept no water, solvent or probing tool. Wipe the casing dry and leave the grid unobstructed, because a starved burner is a burner that will not light. This is also why IOLITE tells owners not to vape with the WISPR 2 still inside its pouch.

8. Watch the gauges: A tank refills in about ten seconds and runs two and a half hours, and fuel windows sit on both the front and back of the body, so top up between sessions rather than partway through one.