G-Shock Watch G-Squad Bluetooth GBA-900-4AER. This model can measure distance using an accelerometer while linked with the GPS function of a smartphone via Bluetooth. Once you take measurements with a smartphone, the next time you will be able to measure distance with the watch alone. Distance and running time measurements are used to calculate your pace, and an auto lap feature automatically records the time it takes to cover a specific distance. You can also check your activity history by linking with an app running on your smartphone. The app also helps to simplify the configuration of watch settings and training management. A 5-level exercise intensity graph and a daily goal attainment rate help keep you motivated. Super Illuminator face illumination keeps face information easy to read, even in the dark. The bands soft urethane material improves the fit to the wrist, and vent holes improve breathability. This watch connects with your phone via Bluetooth to support auto time adjustment, phone notifications, step tracking, and other functions throughout the day. Battery life is approximately two years between replacements.