nestor is a 2mm biometric module that lives beneath the caseback of your mechanical watch. Heart rate, blood oxygen, HRV, skin temperature, activity — captured continuously, invisibly, all day.
The piece on your wrist is the one object you didn't pick by algorithm. It's the watch you saved for, inherited, or chose carefully. It belongs there.
nestor was built so it stays. The module sits beneath the caseback, sealed and silent. The watch keeps doing what watches do. The data shows up anyway.
The whole module is engineered around a single rule: the watch stays the focal point. Three layers do the work, none of them on top.
A hypoallergenic titanium upper shell sits against the back of your watch. No adhesive. No modification. Nothing that would void a warranty.
Optical biometric sensors and a motion sensor measure throughout the day, syncing to your phone in the background.
The skin side is one smooth piece of biocompatible epoxy — sealed, soft, and comfortable from morning to night.
Every angle, every millimeter, every edge — engineered so the watch stays the focal point.
The dive watch from your father. The first piece you saved a year for. The one you wear every day without thinking. nestor was built so none of them ever have to sit in a drawer.
No second wrist. No replacement piece. The one you already wear keeps doing what it does — only now it does more.
2mm thick. 20mm across. Hidden entirely beneath the caseback. You'll stop noticing inside a day.
No adhesive. No modification. No warranty implications. Slip it off for service, then slip it back on.
Every dimension exists for a reason. Small enough to vanish, capable enough to matter.
Fits beneath the casebacks of most modern dive, dress, and sport watches.
A barely perceptible addition to your watch's profile. Beveled edges keep it comfortable.
Two weeks of continuous tracking per charge. Top it off overnight.
Showers, swimming, daily wear. The same conditions your watch is already rated for.
Aerospace-grade titanium. Hypoallergenic, corrosion-proof, virtually weightless.
Lighter than a wedding band. You'll forget within a day.
Daytime, continuous, in the background. nestor focuses on the metrics that change how you train, recover, and notice when something's off — and leaves the rest.
Beat by beat, all day. Resting, active, and recovery zones classify themselves.
Measured continuously, not just when you ask. The trend data only constant wear can capture.
Heart rate variability — the clearest signal of how recovered your nervous system actually is.
Subtle shifts often appear here first — before you feel a thing. Tracked in your unit of choice.
Steps. Movement. Energy burn. Workouts classify themselves — no buttons, no manual logging.
A single morning number that captures readiness, strain, and recovery. The trend lines do the rest.
The questions that come up most. If yours isn't here, reply to the confirmation email — we read every one.
Invitations open in the order they're received. Joining costs nothing and commits you to nothing — it just means you're at the front when production ships.
Free·No payment·No spam·Cancel anytime