Discover the G-Shock GAB2100-1A 'CasiOak', a remarkable timepiece. It's built tough with a carbon/resin case and bezel, and a resin band. Powered by tough solar energy, it offers long - lasting performance. With 200 - meter water resistance, it's perfect for various water activities. The smartphone link feature via Bluetooth keeps you connected, allowing access to world time in around 300 cities, time and place details, reminders, and a phone - finder function. It comes with a double LED light for clear visibility in the dark and a full auto - calendar until 2099. Other features include a stopwatch, timer, 5 daily alarms, and a mute function. It has a case size of 48.5 × 45.4 × 11.9mm and weighs only 52g. With power - saving mode and an accuracy of ±15 seconds per month (without mobile link), it's a reliable companion. The hand - shift feature and multiple display options add to its usability.

Using your G - Shock GAB2100 - 1A 'CasiOak' is a breeze. To connect it to your smartphone, just turn on Bluetooth on your phone and follow the pairing instructions. For setting the world time, access the world - time function on the watch and select your desired city. The stopwatch and timer are easy to operate; simply press the corresponding buttons. The double LED light can be activated when you need to see the time in the dark. When it comes to alarms, you can set up to 5 daily alarms according to your schedule. To mute the button operation tone, use the mute feature. As for maintenance, keep it clean with a soft cloth. Avoid exposing it to extreme temperatures and strong impacts. If you're not using it for a long time, turn on the power - saving mode to preserve the battery. The watch has a rechargeable battery, and in normal use, it can last about 7 months without light exposure after a charge. In total darkness with power - saving on after a full charge, it can last up to 18 months. Just follow these simple steps, and your watch will serve you well for years.