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Technical specification

Operating time with full charge

Up to 8 days with 24/7 activity tracking and 1h/day training (without smart notifications)

Up to 3 days with 24/7 activity tracking and 1h/day training (with smart notifications)

Type 38 mAh Lithium-polymer, rechargeable, non-replaceable.
Charging USB compliant power supply or computer USB port equipped with USB type A connector.
Charging time to full 90 minutes
Capacity 4 Mb
Examples 12 days of activity and 4 one hour training sessions
7 days of activity and 8 one hour training sessions.
USB Polar custom USB cable

The Polar Loop 2 end of the cable is magnetized: keep it away from credit cards and iron objects.

Wireless Bluetooth Smart®
Operating temperature: 0 °C to +50 °C / 32 °F to 122 °F
Charging temperature: 0 °C to +45 °C / 32 °F to 113 °F
Accuracy of heart rate monitor: ± 1 bpm. Definition applies to stable conditions.
Heart rate measuring range: 15-240 bpm
Water resistance  
Polar Loop 2

20 m

Suitable for bathing and swimming

White and pink bracelets


Min. 140 mm / 5.5 inch
Max. 220 mm / 8.7 inch

Black bracelet


Min. 145 mm / 5.7 inch
Max. 240 mm / 9.4 inch

Weight 38 g / 1.34 oz
Width 20 mm / 0.8 inch
85 LED lights in 5 x 17 matrix
Capacitive touch button
3D accelerometer
Bracelet Materials
Front plate and band

Silicone (pink and white models), Thermoplastic polyurethane (black model)

Front plate decoration parts Acrylonitrile butadiene styrene + electro plating,
Back plate Glass fiber, Polycarbonate
Back plate screws Stainless steel
Back plate connector parts Stainless steel
Buckle Stainless steel


Polar FlowSync Software

To use FlowSync software you need a computer with Microsoft Windows or Mac operating system with an internet connection and a free USB port.

FlowSync is compatible with the following operating systems:

Computer operating system 32-bit 64-bit
Windows 7 X X
Windows 8 X X
Windows 8.1 X X
Windows 10 X X
OS X 10.9   X
OS X 10.10   X
OS X 10.11   X
macOS 10.12   X
macOS 10.13   X
macOS 10.14   X

Polar Flow mobile application compatibility

Polar devices work with most modern smartphones. Here are the minimum requirements:

  • iOS devices with iOS 11 or later
  • Android mobile devices with Bluetooth 4.0 capability and Android 5 or later (check full phone specification from your phone manufacturer)

There is plenty of variation between how different Android devices handle the technologies used in our products and services, such as Bluetooth Low Energy (BLE) and different standards and protocols. Because of this, compatibility varies between phone manufacturers, and unfortunately Polar cannot guarantee that all features can be used with all devices.

Water resistance of Polar products

Most Polar products can be worn when swimming. They are not, however, diving instruments. To maintain water resistance, do not press the buttons of the device under water. When measuring heart rate in water with a GymLink compatible Polar device and heart rate sensor, you may experience interference for the following reasons:

  • Pool water with high chlorine content, and seawater are very conductive. The electrodes of the heart rate sensor may short-circuit, preventing ECG signals from being detected by the heart rate sensor.
  • Jumping into water or strenuous muscle movement during competitive swimming may shift the heart rate sensor to a location on the body where ECG signals cannot be picked up.
  • The ECG signal strength is individual and may vary depending on the individual’s tissue composition. Problems occur more frequently when measuring heart rate in water.

Polar devices with wrist-based heart rate measurement are suitable for swimming and bathing. They will collect your activity data from your wrist movements also when swimming. In our tests, however, we found that the wrist-based heart rate measurement doesn’t work optimally in water, so we cannot recommend wrist-based heart rate measurement for swimming.

In the watch industry, water resistance is generally indicated as meters, which means the static water pressure of that depth. Polar uses this same indication system. Water resistance of Polar products is tested according to International Standard ISO 22810 or IEC60529. Every Polar device that has water resistance indication is tested before the delivery to stand water pressure.

Polar products are divided into four different categories according to their water resistance. Check the back of your Polar product for the water resistance category, and compare it to the chart below. Please note that these definitions do not necessarily apply to products of other manufacturers.

When performing any underwater activity, the dynamic pressure generated by moving in water is greater than the static pressure. This means that moving the product under water subjects it to a greater pressure than if the product were stationary.

Marking on the back of the product Wash splashes,
sweat, raindrops etc.
Bathing and swimming Skin diving with snorkel
(no air tanks)
SCUBA diving
(with air tanks)
Water resistant characteristics
Water resistant IPX7 OK - - - Do not wash with a pressure washer.
Protected against splashes, raindrops etc.
Reference standard: IEC60529.
Water resistant IPX8 OK OK - - Minimum for bathing and swimming.
Reference standard: IEC60529.
Water resistant
Water resistant 20/30/50 meters
Suitable for swimming
OK OK - - Minimum for bathing and swimming.
Reference standard: ISO22810.
Water resistant 100 meters OK OK OK - For frequent use in water but not SCUBA diving.
Reference standard: ISO22810.