The Nemuri Breathwork Necklace — Relaxation On Demand

THE NEMURI 3D PENDANT

The Nemuri Pendant is the world's first wearable Vagus Nerve stimulation device to be fully 3D printed. It requires no batteries, no Bluetooth, no app, no firmware updates, and no charging cables. You simply breathe through it — and that's the whole point.

The internal channel is geometrically tuned to add a precise amount of resistance to the air on the way in and the way out. That tiny resistance is what does the work. It naturally lengthens your exhale, slows your breathing rate down into the parasympathetic-dominant zone (around 4–6 breaths per minute), and gently activates the diving reflex through the soft pressure feedback you feel as you breathe. Within a minute or two of use, most people report a noticeable drop in their shoulder tension and a softening behind the eyes.

It's slim and discreet — about ½ inch wide by 3 inches tall — and disappears under a collar. A cord or chain threads through the integrated side eye, and it's available as a transparent polymer or in precious metal (Silver, 18k Gold, Rose Gold).

SPIN IT IN 3D

Drag to rotate the pendant, scroll or pinch to zoom. This is the real print-ready model — the same geometry that ships to you.

THE STANDARD EDITION

Clean engraving front and back — Nemuri on the face, 眠り (Japanese for sleep / slumber) on the reverse.

THE GOLD-INLAY EDITION

Our bonus edition fills the engraving with gold, so the lettering catches the light against the clear body.

A REAL CHAIN FITS

The side grip is a full-thickness loop, flush with the body and filleted at every junction so there are no weak points to snap. The inner wall is relieved to open the eye up — a satin cord, jump ring, or metal chain link passes through with room to spare.

The bail / grip close-up — a chain link threads cleanly through the eye.

THE SCIENCE — THE "REVERSE VENTURI"

The entire therapeutic effect of the Nemuri lives in a channel you can't see from the outside. Here's exactly what happens inside the pendant when you breathe through it.

A true cross-section sliced from the 3D model. Air enters at the top, travels down the internal channel, and exits at the bottom. Notice the channel isn't a plain straight tube — it pinches inward at three points. Those pinches are the engine of the device.

What a venturi is

A venturi is a channel that narrows to a throat and then widens again. When air is forced through the narrow throat it has to speed up, and — by conservation of energy (Bernoulli's principle) — its pressure drops at the throat. The smoothly widening section afterward (a diffuser) lets the flow slow back down and recover most of that pressure gracefully instead of crashing into turbulence.

The Nemuri borrows the same geometry for a different purpose: to add a small, exact amount of resistance to the breath. The throat is the restriction; the resistance you feel on your lips is the pressure it takes to push air through it. Nemuri's throat is tuned to about 2.6 mm — enough to feel, never enough to strain.

The "reverse" part — why inhaling is easy but exhaling is work

A plain venturi resists air equally in both directions. The Nemuri does not. Each of its three throats is asymmetric — a smooth funnel on the mouth side and an abrupt step on the exit side. That single asymmetry makes the channel behave like a passive one-way valve for pressure — a fluidic diode — with no moving parts:

• Inhaling → easy. Air meets each throat as a smooth contraction (a nozzle: it accelerates cleanly, almost no loss) and flows out through a gentle diffuser that hands the pressure back. The path is streamlined, so inhaling is nearly effortless.
• Exhaling → deliberately harder. Going the other way, the air rushes through the throat and hits a sudden expansion — a sharp shoulder it can't follow. The jet separates and tumbles into turbulence, and that turbulence burns off energy (a Borda–Carnot expansion loss). Burning off energy means it takes more pressure to move the same air — so the exhale meets real, felt resistance.

Because three of these asymmetric throats are stacked in series, the effect compounds — roughly a 2 : 1 ratio, so your exhale meets about twice the resistance of your inhale. It's entirely passive, valveless, and self-cleaning: the same principle used in valveless micro-pumps and conceptually related to the Tesla valve.

In one sentence: the Nemuri lets you breathe in freely and gently slows you down on the way out — automatically, with nothing but the shape of the air channel.

Why that difference matters to your nervous system

That "easy in, slow out" asymmetry isn't a gimmick — it's precisely the breathing pattern that calms the body, and the Nemuri produces it for you:

• A longer exhale raises vagal tone. Your heart rate naturally falls on the out-breath (respiratory sinus arrhythmia). Lengthening and resisting the exhale strengthens that signal and shifts you toward parasympathetic — "rest and digest."
• It settles you into the resonance zone. Resisted exhalation naturally slows breathing toward ~4–6 breaths per minute, the "coherent breathing" range where heart-rate variability and the calming baroreflex are strongest.
• The easy inhale is what makes it sustainable. If inhaling were also hard, you'd feel air-hungry and fight the device. Because the inhale is nearly effortless, you can refill quickly and hold a long, slow exhale — session after session, without strain.
• Gentle pressure feedback on the lips, plus the pursed-lip style of breathing, adds a soft proprioceptive cue and can lightly engage the body's natural dive-reflex calming response.

Nemuri is a breathwork and wellness tool, not a medical device; it supports healthy breathing habits and is not intended to diagnose or treat any condition.

HOW TO USE IT

There's no instruction manual because the device is its own instruction. Lift it to your lips, close them gently around the mouthpiece, and breathe through it slowly and naturally. Most people fall into a 4-second-in / 6-second-out rhythm within the first few breaths. After about 90 seconds you'll feel the shift — a softening in the chest, a longer exhale, a quieter mind. To go deeper, let the exhale run even longer than the inhale and let your shoulders drop on every out-breath.

Three sessions a day of two to five minutes each is more than enough to start retraining your baseline breathing pattern. Clients use it before meetings, during commutes, on flights, before sleep, and after intense conversations. It's quiet, it's discreet, and nobody around you needs to know what you're doing.

HOW TO GET YOUR NEMURI

Prefer to simply buy one on its own? Each pendant is 3D printed and hand-finished in the USA by our partner Shapeways. Visit the Nemuri3D shop →

CARE & MAINTENANCE

Cleaning is simple. Rinse the inside of the channel with warm water after each use, and once a week soak it for a couple of minutes in a mild soap solution before rinsing again. For the precious-metal versions, a soft jewelry cloth keeps the outside polished. Avoid harsh solvents and ultrasonic cleaners.

Because there's nothing to break — no electronics, no seals, no battery compartment — a Nemuri pendant should last you for life with basic care. We've had clients still using their original pieces from our first production run: a device that becomes a permanent part of your daily nervous-system practice instead of another product you eventually replace.

We hope you enjoy the Nemuri 3D Printed Pendant!

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