1. Battery life. The most important thing is the battery life. Some brands claim 5 days of battery life, but I've yet to meet a single brand that can match their claims. Most of them are only good for a day or two. So, before you invest in a smartwatch, find out about the battery life. If you plan to wear it every day, make sure it lasts at least a day. 2. Operating System. The watch OS is also very important. It is very important that you should buy a watch that has an operating system that can work on the same platform as your mobile phone. So you can easily control your smartwatch and mobile phone together. 3. Features: If you are a sports enthusiast, you should opt for a smartwatch that supports fitness tracking. You can also choose a watch that can connect to your heart rate monitor. If you want a watch for entertainment purposes, choose one with built-in games. Smartwatches with built-in GPS are also a good choice for people who like to hike. A smartwatch with built-in music streaming capabilities will also be very useful. 4. Screen Size. The screen size is also a very important parameter to consider. If you want to use the watch for work, make sure you choose a watch with a bigger screen. It will be easier to see and interact with the smartwatch. However, if you are going for casual use, you don't need a big screen. Choose a smartwatch with a small screen. 5. Connectivity: Choose a watch with a good Wi-Fi connection. You should choose a smartwatch with a 4G connection. This will allow you to send and receive calls and messages on your smartwatch. 6. Water Resistance: If you want to take your watch with you in the water, make sure it has at least water resistance. If you are going for a sports watch, make sure you choose one with high water resistance. The watch should also have some kind of dustproof and shockproof features. Why buy smart watch? 1. Function In addition to basic functions, smart watches have more and more functions. For example, heart rate detection, blood oxygen detection, ECG, blood sugar detection, sleep monitoring, fall warning, and more. 2. Fashion The appearance of smartwatches is not inferior to that of watches. In the past few years, smart watches have gradually become the fashion trend. 3. Mobile phone control Some smart watches can control mobile phones. For example, making calls, playing music, sending messages, and other operations, you can realize these operations with a tap of a finger. 4. Other Smartwatches can also realize the function of home smart linkage, such as controlling electric kettles, air conditioners and other household appliances. See more details about a1 smart watch in AliExpress Video Page.