Cosinuss One - Wireless In-ear heart rate monitor Black/M
In-ear heart rate measurements instead of limiting strap around the chest? Cosinuss' innovative in-ear fitness tracker combines high measurement accuracy of vital parameters with ergonomics and comfort. Connect your sports watches, bike computers and fitness apps seamlessly and track all your health data during sports with cosinuss. Order now!

€ 129,00

including 16% VAT , free shipping


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Compatible Data - Do not feel like a thousand gadgets that do not work together?

You can pair all your devices that you already own with the ° One - whether it's a heart rate monitor, bike computer or fitness app. With the standard transmissions via Bluetooth or Ant + is not a problem. In addition, you can also export your training data as a CSV to use in your training plans. A smooth integration.

Long Runs - Do not want to spend a few hours giving up your mind?

The cosinuss One lasts longer than you thanks to its extreme lightweight construction and energy efficiency. With only six grams of weight on just under four by four centimeters, it is the smallest and lightest pulse meter in the world. The One will resume up to eight hours and lt in one hour under real conditions.


The sporty use of the cosinuss ° One, e.g. in the rain, with wet hair, after swimming or during heavy sweating is no problem. However, the ° One should not be used for swimming.

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Heart rate variability

The distance between two successive heartbeats can be measured as an RR interval. The RR intervals are not the same length, but are subject to fluctuations. The quantification of these fluctuations is called heart rate or heart rate variability (HRV). In psychophysiology, HRV is considered a biofeedback for stress detection. The HRV also serves to control stress in sports. A high variance generally indicates good health and fitness, but a small variation of the heart rate can indicate a high stress level or over-training.

Sensor technology - Wearable technology for endurance sports

Earconnect - Continuity and precision

The patented earconnect technology allows the monitoring of several vital signs in the outer ear canal. cosinuss° optimised the method of optical heart rate monitoring and applies it in the right place - the ear. This technology allows a mobile monitoring of reliable data of vital signs in many areas of application. No matter if you run a marathon or train for a triathlon event - listen to your body, keep it healthy and fit.

Light weight construction, safety and sportive ergonomics

The cosinuss° One is a light weight and supports your training sitting in your ear. Its fit is explicitely designed for the endurance sports community. As an alternative to the chest strap the cosinuss° One is mainly one thing - user friendly. It does not hurt, it fits comfortably in your ear. It does not restrict you. It is so discreet, you can even wear it continously. It does not disturb you, you can fully concentrate on your training.

Long battery life and short charging time

The cosinuss° One runs as long as you do! No cable, full compatibility with all your gadgets for running , cycling or whatever your passion is. Who does not know that? Many electronical devices pack up exactly then, when you need them. The cosinuss° One includes efficient components and software that only need a minimum of energy. That allows a running time of up to ten hours and makes the °One a perfect companion for endurance athletes. Its recovery period is one hour - how long do you need to rest?

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In addition, the app gives you an overview of your vital parameters. You need these values to plan an optimal performance increase and to get to know your friend even better:

  • Pulse rate (min/dia/max)
  • Cooling temperature (min/dia/max)

The cosinuss ° One app shows you what you really need. Clearly structured - easy to understand!

Overview of the data & amp; History for optimal training results

In addition to displaying the numbers, your heart rate and temperature data can be easily and easily visualized in a diagram. For the overview of your training sessions, you can view all of the training sessions you have completed, and thus make the training success visible over a longer period.

Export the data for individual evaluation

For the overview and creation of your individual training planning you can export the data in the CSV format and on the PC, for example, in Excel or OpenOffice, edit and document it.

Integration - Integrate your data anywhere and build your own app

You have an idea how to make better use of your cosinuss ° One? You would like to build an app exactly? We support you! You are already training with a training software or you have an idea how you would like to have your data visualized or evaluated? No problem! Your data is open for you and is compatible for integration into existing systems.

The cosinuss ° One App is now available free of charge in the App Store and Google Play Store: 

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Temperature sensor

  • Sensing Type: Pt1000
  • Measurement method: Resistor
  • Measurement Accuracy: ± 0.1 ° C
  • Measurement range: 0 to 50 ° C


  • Sensor type: 3-axis acceleration sensor (linear)
  • Measurement Accuracy: ± 0.1962 m / s2
  • Scope: -39.24 to +39.24 m / s2


  • Version: Bluetooth Smart, low energy specification version 4.0
  • Frequency: ISM band 2.4 - 2.485 GHz
  • Transmission power: 4 dBm
  • Signal range: approx. 10 m
  • Connected number of devices: 1 device
  • Data rate: 1 Hz
  • Supported profiles: Battery Service, Device Information Service, Health Thermometer Service, Heart Rate Service


  • Type: Lithium-ion battery
  • Nominal charge: 50 mAh
  • Runtime: about 8 hours
  • Charging time: about 1 hour
  • Standby time: up to 5 months


  • Android Apps: Android 4.3 or higher
  • iPhone Apps: iPhone 4s or higher
  • Smart Devices: all devices that support Bluetooth Smart (4.0) or ANT +


Target Groups: Advanced Users Athletes Beginner
Applications: Biofeedback Fitness Health Heart Rate Running Pro Sports
Product features: Single channel sensor
Product Type: Wearable
Shipping weight:0,30 Kg
Product weight: 0,20 Kg

Cosinus One_User Manual_DE

Cosinus One_User Manual_EN

Datasheet_Cosinus One_DE