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Technical Specification


Battery type: 68 mAh Li-pol rechargeable battery
Operating time: Up to 26 days with 24/7 activity tracking and 1h/day training
Operating temperature: -10 °C to +50 °C / 14 °F to 122 °F
Training computer materials: Device: acrylonitrile butadiene styrene, glass fiber, polycarbonate, stainless steel, polymethylmethacrylate

Wristband: silicone, stainless steel;

Watch accuracy: Better than ± 0.5 seconds / day at 25 °C / 77 °F temperature
Accuracy of heart rate monitor: ± 1% or 1 bpm, whichever larger. Definition applies to stable conditions.
Heart rate measuring range: 15-240 bpm
Water resistance: 30 m
Memory capacity: 60 h training with heart rate depending on your language settings

H7 Heart Rate Sensor

Battery life: 200 h
Battery type: CR 2025
Battery sealing ring: O-ring 20.0 x 1.0 Material FPM
Operating temperature: -10 °C to +50 °C/14 °F to 122 °F
Connector material: Polyamide
Strap material: 38% Polyamide, 29% Polyurethane, 20% Elastane, 13% Polyester
Water resistance: 30 m

Uses Bluetooth® Smart wireless technology.

Your A300 is compatible with the following Polar heart rate sensors as well: Polar H1, Polar H2 (using GymLink technology) and Polar H6.

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.

Check the latest compatibility information from

Polar Flow mobile application compatibility

Check the latest compatibility information from

The Polar A300 training device applies the following patented technologies, among others:

  • OwnIndex® technology for Fitness test.

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.

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.