Asus laptops tend to be fairly universal, to the point you can use a common adapter; I have even test fit Toshiba branded ones on them and it takes; the exception is the thin-and-lights like the ZenBook series.
Any good quality 3rd party adapter like the Targus universal will work, essentially. That said, I still recommend a OEM Asus but if you want a good 3rd party universal it usually isn't an issue.