What sensor is best for me?

You can compare our sensors on this page to ensure you make the right choice!

Do you ship internationally?

Yes, we do! We ship from the Netherlands, shipping cost depends on your location. We offer free shipping within Europe*. For businesses and all other countries, costs are calculated automatically on the website.

How long will it take to get my order?

It depends on where you are. Orders processed here will take a few business days to arrive. Overseas deliveries can take anywhere from 2-14 days. Delivery details will be provided in your confirmation email.

What if the app crash after calibration?

If the app crashes after the 10-second calibration, it may be due to GPS not being enabled on your phone. GPS access is required for the app to function properly. Solution: 1. Ensure GPS is enabled on your phone before starting a session. 2. When prompted for location permissions, grant access to the app. 3. If the issue persists, manually enable GPS for the Train.Red app in your phone’s settings.

Why can't connect my sensor via Bluetooth?

If you've followed the recommended troubleshooting steps and your sensor still won't connect, check if other Bluetooth devices are interfering with the connection. One common issue occurs with smartwatches. If a smartwatch is charging, it may automatically keep the sensor connected, even in standby mode, preventing your phone from establishing a connection. Solution: 1. Try disconnecting the charging cable from your smartwatch. 2. If the issue persists, enable Airplane Mode on the smartwatch. This will prevent it from interfering with the Bluetooth connection. 3. Once the smartwatch is in Airplane Mode, try reconnecting your sensor to the phone. This should resolve the issue and allow your sensor to connect properly. If you continue to experience problems, please contact our support team.

Find your muscle oxygen sensor package

Muscle Oxygen Sensor Packages

Compare Train.Red FYER 2.0, FYER 2.0 PRO and PLUS 2.0 muscle oxygen (SmO2) sensors. Choose a package for individual training, athlete monitoring, performance testing or lab use. Every package includes the free app.

Find your packageQuestion 1 of 4

Who will you be measuring?

Choose one option.

Prices below are for FYER 2.0 PRO — switch above to compare lines.

Solo – muscle oxygen sensor package

Build your own SmO2 baseline

€999

ONE-TIME

A simple way to start measuring muscle oxygen (SmO2) at one site.

1x sensor
Free App
Charging cable

Buy now

Core – muscle oxygen sensor package

New to muscle oxygen, guided start

€1,099

ONE-TIME

A guided starting package for athletes learning to use muscle oxygen data.

1x Full Set Sensor (Charging Cable, Strap Pack S-M-L, 2 Plug and Travel Pouch)
Free App
Muscle Oxygen Course

Buy now

Starter – muscle oxygen sensor package

Add a second sensor for bilateral or client-facing testing

€1,999

ONE-TIME

Two sensors for bilateral comparisons or testing clients and athletes.

2x Full Set Sensor (Charging Cable, Strap Pack S-M-L, 2 Plug and Travel Pouch)
Free App
Muscle Oxygen Course
30-min 1-on-1 session

Buy now

Professional – muscle oxygen sensor package

4 sensors, small groups up to full squads

€3,699

ONE-TIME

Four sensors for coaches, performance staff and teams monitoring multiple athletes.

4x Full Set Sensor (Charging Cable, Strap Pack S-M-L, 2 Plug and Travel Pouch)
Free App
Muscle Oxygen Course
2x 30-min 1-on-1 data sessions

Buy now

Custom – muscle oxygen sensor package

For labs, teams & trainers or more than 4 sensors

On request

A tailored muscle oxygen monitoring setup for labs, clinics, teams and trainers needing more than four sensors.

A tailored, total solution across sensors, testing and reporting

Muscle oxygen sensor FAQs

What is the difference between FYER 2.0, FYER 2.0 PRO and PLUS 2.0?

FYER 2.0 is the entry-level line (10 Hz), FYER 2.0 PRO is built for precision (100 Hz), and PLUS 2.0 is the 6-channel line for lab use.

Which package should I choose?

Solo is one sensor for trying out muscle oxygen at a single measuring site. Core is the full set with the Muscle Oxygen Course for a guided start. Starter adds a second sensor for bilateral or client-facing testing. Professional covers 4 sensors for small groups up to full squads. Custom is for labs, teams and trainers with more than 4 sensors, on request.

What is included in the packages?

Every package includes the free app. Solo includes one sensor and a charging cable. Core, Starter and Professional include the full set sensor and the Muscle Oxygen Course. Starter adds a 30-min 1-on-1 session and Professional adds two 30-min 1-on-1 data sessions.

Are the prices one-time?

Yes. The prices shown are one-time prices. The Custom package is quoted on request.