The questions we would ask.

Partly. Controlled chamber studies — Satish 2012, Allen 2016 — found substantial decrements in complex decision-making at 1,000 and 2,500 ppm. Independent replication has been inconsistent, and a 2019 review co-authored by the original lead author is openly sceptical about direct effects below roughly 5,000 ppm. What is not disputed: CO₂ is a reliable proxy for ventilation rate per occupant, low ventilation is independently linked to worse symptoms and performance, and you cannot perceive any of it without an instrument. We set out the full picture, including the papers that undercut us, on the science page.

Because the measurement is not contested — only the size of the cognitive effect is. Ventilation is a real, controllable variable in the room you spend nine hours a day in, and right now you have no visibility into it at all. The instrument costs less than two days of a senior engineer's time. Even under the sceptical reading of the literature, knowing that your closed office hits 1,600 ppm by 11am is worth having.

A directional figure we derive by interpolating between the exposure conditions published in Satish 2012, anchored to their reported effect sizes on the Strategic Management Simulation measures. It is a way of making a ppm number legible. It is not a clinical measurement, it is not personalised to you, and we never present it as either.

Three reasons, and only the third is about materials. First, the sensor: a dual-channel NDIR cell with a sealed reference and pressure compensation holds calibration over years, where a single-channel cell drifts and quietly leans on auto-baselining to hide it. Second, the rest of the suite — CO₂ alone tells you about ventilation but nothing about what is in the air being ventilated. Third, it is machined aluminium with a transflective display because it sits on your desk for a decade, and a grey plastic box with a blue LED does not survive that context.

No. Take it out of the box, plug it in, and every sensor, the display, the alerting and two years of local history work with the radio switched off and no account created. Networking unlocks the app, the local API and Signal. It is not a licence to operate hardware you own.

It has no fan and no moving parts of any kind. Air moves through a convective chimney path machined into the chassis. It makes no sound at all.

Core runs continuous automatic baseline correction, which is sufficient for a space that sees outdoor air at some point each week, and accepts a manual single-point calibration outdoors if you want to force it. Pro ships calibrated against a traceable reference with a per-unit certificate, and we recalibrate annually at cost with a loaner unit while yours is with us.

Core, unless one of these applies: you need the reading to stand up to a third party, you want formaldehyde or NO₂ specifically because of new fit-out or a gas hob, you are on a ground floor or basement and should be measuring radon, or you want to pull raw data into your own stack over a local API. Those are Pro. Otherwise the extra €300 buys you precision you will not use.

Nothing. We take an email address and hold you a founding place — no payment, no card details, no obligation. When production is confirmed we email you with a link to buy, and you decide then. If you ignore that email, nothing happens to you.

The Founding 500 ship in Q1 2027, in reservation order. General availability follows in Q2 2027. If a date slips we will say so in an email that leads with the new date rather than burying it in paragraph four.

The first 500 units. Engraved sequential serial on the base, the factory calibration record for your specific unit, OptiBreath Signal for life rather than the first year, and first position in the shipping queue. It costs the same as a standard unit — the waitlist is simply how we decide who gets offered one first.

Once units ship: 60 days from delivery, for a full refund including return shipping, for any reason or none. An instrument you are talked into is worth nothing to us — we would rather have the unit back and your honest reason why.

Because that is all a waitlist needs, and every extra field costs us people who would genuinely want one. We are not building a profile of you, we are building a list of people to email when there is something to buy. Name, shipping address and payment details are collected at the point they are actually required, which is not today.

By default, only you — the cloud is off until you switch it on. If you enable it, data is stored in the EU, never sold, never brokered, and never used to build an advertising profile. Benchmarking is opt-in and aggregated. You can export everything at full resolution and delete the account and its data from a single screen.

It carries on working, because it never depended on us. Everything runs locally. We additionally commit to publishing the local API specification, the service manual and the firmware signing tooling if we ever wind down, so the community can keep it alive. A €390 instrument that bricks when a startup fails is not an instrument.