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Technical Specification


Battery type: 100 mAh Li-pol rechargeable battery
Operating time:

Up to 4 days with 24/7 activity tracking, continuous HR tracking and 1h/day training without Smart Notifications on.

Operating time in training mode: Up to 13 hours with mobile GPS on. Up to 32 hours with mobile GPS off.
Operating temperature: -10 °C to +50 °C / 14 °F to 122 °F
Charging time: Up to two hours.
Charging temperature: 0 °C to +40 °C / 32 °F to 104 °F
Fitness tracker materials: Device: thermoplastic polyurethane, acrylonitrile butadiene styrene, glass fiber, polycarbonate, stainless steel, glass

Wristband: silicone, stainless steel, polybutylene terepthalate, glass fiber

Watch accuracy: Better than ± 0.5 seconds / day at 25 °C / 77 °F temperature
Heart rate measuring range: 30-240 bpm
Water resistance: 30 m
Memory capacity: 60 h training with heart rate depending on your language settings

Uses Bluetooth® wireless technology.

Your A370 is compatible with the following Polar heart rate sensors as well: Polar H6, H7, H10 and OH1.

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.

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.