It is Sim Card enabled with a SIM card slot. The watch uses WiFi and can download apps in play store. You can download a call and text App like "textme" with a free or paid number to call and text.
This is an option in case your SIM card or your network carrier won't work with the watch. Please look up all the pictures and see the apps I was able to download and connect to my different account. This is a mini device so understand that it can't download everything you want. You have a lot of options to save the battery life.Put your watch brightness on low. Put your watch on high power saving mode when you're not using it. 1 TK watch 4G Ram 64GB wifi. Any questions please feel free to ask.