This smart watch by #DOROIM is great for the price. I like I don't necessarily need a sim card and a new cellphone number. I can simply use my bluetooth and connect my cellphone that way in order to place and receive calls. It also has both a sim card slot and a TF slot. This also has a calculator, pedometer and s built in camera. The camera isn't a high pixel camera being less than 1 pixel but it is there. For only $20.99 this is a good buy.