Genuine Asus VivoBook S400 chargers are listed below, just check the model of your Asus notebook, laptop in most of the these models cases the VivoBook, this is normally displayed underneath and will state for example Asus S400 VivoBook, which would mean you can simply check the original Asus S400 ac adapters located just underneath as these fit most models or look below for your full part number.