The new Diesel Full Guard 2.5 has a 47mmx56mm casing which is bigger than most Wear OS watches, and there’s a 1.39-inch display at the center of that. This new refresh of the watch also includes NFC for Google Pay support, a heart rate sensor, and built-in GPS. Diesel also says this watch will last two days on a charge from the 300mAh battery. The watch also has 3ATM water resistance.
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. 
Smart watches are here to change the way you live. Now you can power through your workouts while the latest technology keeps track of your every move, check your calendar and keep an eye on the weather forecast wherever you are. You can also sync your smartphone with your watch, so you can check your texts, see who’s calling and receive notifications while keeping your iPhone 6 Plus safely tucked away.
Garmin, known primarily for its GPS and fitness devices, has taken one step closer to full-featured smartwatches with their Vivoactive 3 Music. This model doesn't run on Wear OS (Google's increasingly-popular OS for wearables), but it does offer thousands of free apps, watch faces, and more via Garmin’s ConnectIQ store. The Vivoactive 3 Music also comes preloaded with 15 sports apps to monitor your progress whether you're running, swimming, lifting, or doing yoga — because, at its core, Garmin is still all about fitness tracking
Built-in GPS and a great workout coach make the Huawei Watch 2 a great companion on long runs and intense workouts. You can leave your phone behind, too, thanks to onboard music storage and the ability to connect Bluetooth headphones to the watch. Like the LG Watch Sport, the Huawei Watch 2 has an LTE version, but unfortunately, Huawei isn't selling that model in the US yet.
Basically, smartwatches are wearable-technology devices that maintain a relatively persistent wireless connection to your mobile device—usually a smart phone—and can receive notifications of incoming calls, texts, instant messages, social-network updates, and more, from that device. Some can also let you accept and conduct phone calls right on the watch. And even newer models (the Samsung Gear S, for one) can act as smart phones all on their own, without needing a paired phone nearby.
Huawei’s Watch 2 looks like a logical follow-up to the original Huawei Watch, a former pick in this guide. It adds built-in GPS capability, plus NFC for mobile payments, and it ships with Android Wear 2.0. The problem is that the Huawei Watch 2’s bezel does not rotate, and it has no rotating crown to take advantage of Android Wear 2.0’s scrolling interfaces. That wouldn’t be so bad if the thick, notched bezel weren’t significantly raised around the screen, making it more difficult than it should be to swipe between screens, scroll through apps, or perform pinpoint taps near the edge of the screen. Beyond that, the watch is thick (12.6 millimeters, or 2.6 mm more than the ZenWatch 3, though that’s still slightly thinner than the original Huawei Watch), and it seems slower to respond to input and to launch apps than other modern Wear OS watches. It doesn’t seem worth its price for most people.
Apple Watch Series 3: If you are an iPhone user and generally exist in Apple’s ecosystem, it makes sense to get an Apple Watch. The design quality is exceptional and the Watch makes a nice pairing with your iPhone as materials and design elements are common to both. Apple’s Health app covers most of the bases when it comes to tracking your essential fitness and activity indicators - nutrition, sleep, physical exercise, but Apple has gone further with HealthKit, which allows health and fitness apps downloaded from the App Store to share data with each other. Apple has committed to Watch, and its attention to practical and eye-pleasing design as well as useful tracking features is commendable. ($529)
Fitbit's Versa is a sleek, stylish smartwatch that works with both iOS and Android and costs less than $200, which makes it the best value smartwatch you can buy. The watch lasts four days on a charge, offers female health-tracking, advanced sleep-tracking and an app store with popular apps such as Starbucks and Pandora. You can even store music offline to listen to while you work out.