Instagram

TikTok

Facebook

Order Now

Personal Sun Intelligence UV Sensor

Get the good out of the sun. Own your light.

Vitamin D

Personal UVI

Circadian Ligh

Live UVB and UVI

"I Don't Put My Name On Anything I Don't Fully Believe In."

“I Don’t Put My Name On Anything I Don’t Fully Believe In.”

✦ Lauryn Bosstick, The90 Investor and Creator of the Skinny Confidential.

The90 turns the light your skin actually gets, the vitamin D and morning light you want and the aging and burning you don't, into one daily Sun Score from 0 to 100. Aim for The90.

The90 is a personal sun intelligence system. A jewelry-grade sensor and a connected app measure the Personal UV your skin actually gets, then turn it into one number you can act on.

Sunlight gives. Sunlight takes. The difference is knowing your dose.

The UV Index tells you what may be happening outside. The Gem shows what is happening to you.

Stop guessing. Start understanding your light.

Sunlight is essential.

It helps support vitamin D production, regulates your circadian rhythm, and connects your body to the natural day.

But the same light can also burn your skin and accumulate as long-term UVA exposure.

Sunlight is essential.

It helps support vitamin D production, regulates your circadian rhythm, and connects your body to the natural day.

But the same light can also burn your skin and accumulate as long-term UVA exposure.

Personalized to your skin recommendations based on your unique skin profile, genetics, habits, and sensitivities.

Tracks the rays that matter. Measure both UVA (aging) and UVB (burning) in real time – including the exposure that quietly adds up through windows, cars, errands, and more.

Built for everyday life. Wear it with your existing jewelry, pair the Gem with The90 app, and get guidance on when it's time to reapply, cover up, or get out of the sun.

One Platform. Every answer you need. The Gem sees it. The Score explains it. You own it.

The jewelry-inspired UV sensor that tracks what your skin actually experiences, so you can protect how you age while harnessing the health benefits of the sun.

Finishes

Track what silently adds up

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Water Resistance

Тут про аксесуары клип и кепку

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Switch. Easier

Track what silently adds up

The90 Gem was designed as a timeless piece of jewelry women actually want to wear. Elegant, customizable, and made to fit every moment.

Jewelry Design

Track what silently adds up

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Advanced Sensors

The jewelry-inspired UV sensor that tracks what your skin actually experiences, so you can protect how you age while harnessing the health benefits of the sun.

Finishes

Track what silently adds up

The90 Gem was designed as a timeless piece of jewelry women actually want to wear. Elegant, customizable, and made to fit every moment.

Jewelry Design

Track what silently adds up

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Water Resistance

Track what silently adds up

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Advanced Sensors

Тут про аксесуары клип и кепку

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Switch. Easier

Stop guessing what your skin needs. The90 shows your UV exposure in real time, and tells you what to do about it.

Know your sunburn window

See your estimated time to burn based on real-time UVB exposure (rays that cause sunburn), sunscreen use, and skin profile.

Track what silently adds up

Monitor UVA exposure (rays linked to premature photoaging and long-term skin damage) even when you can't feel or see it.

Build smarter sun habits

See your daily sun exposure patterns, track how your habits add up, and get personalized recommendations on how to protect your skin over time.

Tracks the rays that matter. Measure both UVA (aging) and UVB (burning) in real time – including the exposure that quietly adds up through windows, cars, errands, and more.

Meet The Gem

The jewelry-inspired UV sensor that tracks what your skin actually experiences, so you can protect how you age while harnessing the health benefits of the sun.

Meet The Gem

The jewelry-inspired UV sensor that tracks what your skin actually experiences, so you can protect how you age while harnessing the health benefits of the sun.

POV: your day in the sun

Checking UVI on your phone gives you an idea of the weather, but it doesn’t tell you what you’ve actually been exposed to. The90™ Gem tracks both UVA & UVB exposure in real time and provides insights along the way.

7:42 AM

First light

You step into first light. The app begins tracking the circadian light that helps set energy, mood, and sleep.

Circadian light · Day begins

9:15 AM

The commute

Twelve minutes outside. It’s cloudy. The Gem records the light that actually reaches you—not the forecast for your city.

Personal exposure · Not weather data

12:30 PM

Peak

Lunch outside. Personal UV intensity rises. The app tells you there’s still time to enjoy it—and when protection will matter.

Enjoy now · Protect next

4:20 PM

Errands

A half hour here, twenty minutes there. Small moments stop disappearing into guesswork.

Everyday exposure · Understood

6:45 PM

Golden hour

Vitamin D progress. Circadian light. UV balance. The app shows the benefits you gained—not only the limits you avoided.

Sun-positive guidance

9:30 PM

The wrap

At the end of the day, you know what you received, when you protected yourself, and how your habits are changing over time.

Confidence · Not fear

Personalized brief, just for you

Stay on top of your day with hyper-personalised insights at a glance directly from FlexWindow. Now Brief doesn't just intelligently learn your routines, it can also be customised for briefings you'd like to receive based on your interests such as weather, health and more.2

Create your skin profile

The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.

Track UVA & UVB

Know exactly what rays have hit your skin throughout the day, and what that means for your specific skin type. This way you can apply sunscreen or cover up before you burn, and get insights on what you can do to mitigate the aging effects of the sun.

Harness the benefits

We know now more than ever that the sun is vital to our health. With The90™ you can track these benefits like Vitamin D production, so you can maximize the benefits without risking damage from harmful UVA rays.

Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.
Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.
Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.

Designed to Go Wherever You Do

Made to look as good as it performs, The90™ Gem blends seamlessly into your everyday jewelry stack, so you can wear it from workdays to workouts to weekends in the sun and everything in between.

Indoor

Indoor

Outdoor

Outdoor

Active

Active

Lounging

Lounging

Built With Leading Skin and UV Expert

Dr. Richard Weller

World Renowned UV Specialist & Dermatologist

Chief Medical Officer

See What Your Skin Feels

Checking UVI on your phone gives you an idea of the weather, but it doesn’t tell you what you’ve actually been exposed to. The90™ Gem tracks both UVA & UVB exposure in real time and provides insights along the way.

Create your skin profile

The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.

Track UVA & UVB

Harness the benefits

Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.
Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.
Create your skin profile
The90™ app walks you through a series of questions that help us build your specific skin profile. Genetics, habits, and sensitivities all play a role in how your skin reacts to the sun.