It has all the same core fitness and sports tracking as the Series 3, including built-in GPS and a swimproof design. You can also expect improvements in run tracking and new supported activities like yoga and hiking. It comes packing LTE once again so you can take it out sans iPhone and still make/receive calls, get texts and all other notifications you would on your phone. A new speaker should also make Siri chats and phone calls sound louder and clearer.
Waterproof to 165 feet and tested to military standards for durability, it includes features like a digital compass, altimeter, and barometer that you won’t find in most other smartwatches, as well as more standard tools such as GPS. The WSD-F20 can also function as a flashlight — handy in an emergency — and lets you download maps for offline navigation when you’re far from the nearest cell signal.
The headline features are the new ECG monitor that unlocks the ability for serious heart health monitoring. It's been FDA cleared, so the feature can be used to detect heart rhythm irregularities - however, it's only in the US only for now. There's also a new fall detection mode that can let users access Siri to contact emergency services or a emergency contact. Apple's new smartwatch offers groundbreaking features and an improved design that makes it the standout option for iPhone owners right now.
The top smartwatches that debuted at the 2017 Consumer Electronics Show included the Casio WSD-F20, Misfit Wearables Vapor and the Garmin Fenix 5 series. Apple released on September 22, 2017 their Apple Watch Series 3 model which offers built in LTE cellular connectivity allowing phone calls, messaging and data without relying on a nearby smartphone connection. 
For all of you outdoorsmen, Casio returned to IFA this year with its latest Pro Trek watch. The Casio WSD-F30 takes the same great features of previous generations and slaps them inside of a slightly slimmer body. The 60.5mm × 53.8mm × 14.9mm body is still pretty huge, but it’s considerably smaller than what came before it and still maintains 5ATM water resistance, MIL-STD-810, and even low-temperature resistance.
We test every new smartwatch to gauge its design and comfort. If it’s not stylish and comfortable enough to get you from an early morning workout to the office to a night out, you probably won’t wear it every day. Most smartwatches are also fitness trackers, so we put all of its sensors to the test, from step counts to heart rate to GPS (when applicable).