They do not have a button, they do not need to be filled or charged, there is no need to change or adjust anything in them, these disposable e-cigarettes are extremely simple and practical. The X4 is the ideal companion for anyone who just wants to enjoy a vaping without any need to take care of an e-cigarette. There are four distinctive flavors on the menu. With the X4, all you have to do is take a puff and enjoy the easiest vaping.