Setup guide
Setting up your ring and scale.
Two devices, one app. Charge your HART Ring X2, step on your SENSE Pro, and get both talking to FITTR ONE in just a few minutes.
First things first
Before you start.
1 · The app
Get FITTR ONE
Both devices connect through the FITTR ONE app, so download it first and log in. Your phone needs Android 5.0 or iOS 10.0 (or newer) — update it if it’s older.
2 · Your phone
Turn on Bluetooth
Keep Bluetooth on while you set up, and tap Allow when the app asks for permissions. That’s how your phone finds your ring and scale.
3 · Your devices
Charge before you pair
The ring needs to be fully charged before its first use. The scale needs at least 2 hours on its charging cable.
Part 1
HART Ring X2
Your ring and charging case arrive in “shipping mode,” which just means they aren’t switched on yet. Four quick steps wake them up and connect the ring to your app.
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1
Wake it up and charge it
- Place the ring in the charging case with the mount facing down. Press gently until it clicks.
- Plug the USB-C cable into the charging case and connect the other end to a power source.
- Then unplug the cable and plug it in a second time. A case in shipping mode needs to be plugged in twice to activate.
- Leave the ring to charge fully before you move on.
Tip: the charger needs to have some power for activation to work. If you ever factory-reset the ring, charge it fully before switching it back on.
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2
Wear it the right way
Wear the ring on the same finger you confirmed with your sizing kit. Turn it so the sensor faces the palm side of your finger — not the top.
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3
Download the FITTR ONE app
Once the ring is fully charged, get the FITTR ONE app from the App Store or Google Play (links above) and log in. Make sure your phone runs Android 5.0 / iOS 10.0 or newer.
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4
Pair the ring with the app
- Turn on Bluetooth on your phone.
- Open FITTR ONE, log in, and tap Continue on the “Connect your device” screen.
- Allow the permissions the app asks for: Bluetooth, location, and nearby devices.
- The app searches for your HART Ring. When it appears, pull down on the screen to connect.
- Once it’s paired, the ring’s light blinks green 3 times. If the battery is under 20%, it blinks red 3 times instead — put it back on the charger.
A green light blinking during setup means the connection is being made. The HART Ring X2 connects over Bluetooth 5.0.
And you’re done!
Your ring is activated, charged and paired. Now just wear it day and night and let it work on your health.
Stuck on activation?
Charging case troubleshooting.
The case won’t activate+
A case in shipping mode needs its USB-C cable plugged in twice to activate: plug in, unplug, plug in again. The charger also has to have some power, so connect it to a working power source to finish activation.
The ring and the case are both out of power+
If the ring’s battery is completely drained, connect the charging case to power. If the case has enough battery, unplug it after a few seconds to start charging the ring. If the case is empty too, leave it plugged in so it charges both the ring and itself.
How do I know when the ring is fully charged?+
With the USB-C cable plugged in, a steady green light means the ring is fully charged. A blinking light means it’s still charging.
The ring’s charging light is blinking fast+
This happens when the charging case is low on battery but the ring is already fully charged. The ring’s light blinks quickly instead of holding steady, and the charging icon in the app blinks faster than usual too. Plug the case in to recharge it.
Part 2
SENSE Pro Smart Scale
More than a weigh-in. The SENSE Pro looks at 50+ measures of your body composition — including visceral fat, muscle mass, hydration, protein, bone mass and body age — and syncs them to FITTR ONE.
In the box
- SENSE Pro Smart Scale
- Charging cable (USB to USB-C)
You’ll also need a 5V/1A USB power adapter to charge it — one isn’t included.
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1
Unwrap and charge it
- Remove all the packaging, including the protective plastic film.
- The scale runs on a built-in rechargeable lithium battery. Before first use, charge it with a 5V/1A adapter for at least 2 hours.
- Place it on a hard, flat surface and step on. Light pressure (3 kg / about 7 lb or more) wakes it up and the screen lights up.
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2
Pair it with the app
- Turn on Bluetooth on your phone.
- Open FITTR ONE and agree to the user agreement.
- Log in or register, then enter your personal details.
- Tap Smart Scale, then step on the scale. Pairing happens automatically.
If it doesn’t connect, check that Bluetooth is on and that you’ve allowed the app’s permissions.
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3
Take your first measurement
- Stand barefoot on the electrode areas with clean, dry feet.
- Hold the handle by its electrode areas with a clean, dry hand on each side.
- When the screen prompts you, raise the handle out in front of you at chest height and stay still while it gathers your body metrics.
- Your results appear on the scale’s display and in the app.
Want to measure again? Step off, wait for the display to show 0.00, then step back on — or tap + Measure in the app.
And you’re done!
Your scale is synced with the app, so you can check your weight and full-body composition any time. Everything it shows is for wellness tracking only — not for medical diagnosis.
Better readings
Get the most accurate numbers.
Do
- Use it on a hard, flat floor and check the screen reads “0.00” before you step on.
- Stand barefoot with clean, dry feet, both feet evenly on the electrode areas.
- Stand straight and spread your weight evenly.
- Weigh in at the same time of day, under similar conditions.
- Pick kg or lb in the FITTR app, or with the button on the scale.
Skip the reading if…
- You just finished strenuous exercise, a heavy meal, alcohol, or a bath or shower.
- You have a fever or feel unwell.
- Your feet or the floor are wet or dirty.
- The scale is on carpet or an uneven floor.
- You’re in a dusty, damp or dirty area.
- You’d be jumping on or standing on the edge — only steady, static pressure works.
Safety first. The scale uses bioelectrical impedance analysis (BIA). The current is safe, but don’t use it if you have a pacemaker, ECG monitor or other implanted medical device, or you’re pregnant (as a precaution). Also avoid using it when wet, in temperatures above 60°C (140°F) or near heat or fire, and below 5°C (41°F) or near magnetic fields such as a microwave.
The SENSE Pro is for general wellness use only. It isn’t a medical device — talk to your doctor about any health concerns.
If something’s off
Scale troubleshooting.
The scale won’t turn on+
Make sure it’s sitting on a hard, flat surface — it wakes with pressure. If the screen still stays dark, the battery may be empty, so charge it with the cable.
Body-fat numbers aren’t showing+
Stand barefoot with clean, dry feet and make sure both feet are in full contact with the electrodes.
The readings look wrong+
Check that your feet and the scale’s surface are both clean and dry. Then measure again once the scale resets to “0.00”.
Nothing on the screen, an error, or missing info+
Check that Bluetooth is turned on in your phone, and that the scale is charged and powered correctly.
The scale shut off suddenly+
It may have overheated from continuous use. Let it cool down, then switch it on again.
I’m seeing an overload warning+
The scale supports a total weight of up to 180 kg (397 lb). Make sure the load on it doesn’t go over that limit.
Care
Cleaning & storing
- Wipe the surface with a soft cloth slightly dampened with water. Don’t soak the scale or use chemical solvents.
- Store it somewhere cool and dry, away from humidity, direct sunlight, and heat sources like radiators or stoves.
Recycling
Recycling & disposal
- Don’t throw the scale or its battery in household trash. It has a built-in rechargeable lithium battery and electronic parts.
- Take it to a local electronics recycling or battery drop-off point, and follow your local rules for e-waste.
Need help with setup?
We’re here to get you up and running.