The device has an electronic display to present information to the user.
Dustproof/water resistant at depth equal to or greater than 1 meter.
These devices will not experience water damage, e.g. in the shower. Devices which can withstand more water pressure are better for swimming or diving.
Resistance to sweat makes it ideal for use while doing sports.
Polar RCX3 GPS
This measures barometric air pressure. It can predict weather changes, for example a sudden drop in air pressure could mean a storm is coming. When calibrated correctly it can be used to determine altitude, which helps GPS devices to lock on quicker and with greater accuracy.
A compass is useful in games, map and navigation software.
3D compass is a compass that will show accurate readings also when the compass is tilted. Therefore you don’t need to keep the compass on level ground to get steady readings.
It tracks how far you travel.
It can detect changes in elevation, such as when you are climbing stairs.
An indicator shows you when the device has low battery.
The battery can be recharged and used over again.
A solar battery takes its energy from light, and stores it in a self-recharging battery which never needs to be changed.
With a stopwatch you can time yourself.
An altimeter can track elevation, ascent and descent using GPS or air pressure. It is particularly useful if you travel on hills or mountains.
With a world timer you can easily see the time all over the globe. It is useful if you are travelling through different time zones.