I know very little about this computer and apple lap tops, I've had a few ipods and iPad, but could never get a apple lap top, they cost a lot but it's worth it , apple is great. That being said, I can tell you that this unit came from a really good home always well cared for.  I am selling this cheap cause, it's an older model, but in beautiful condition with decent battery and charger, but, it has a soft ware issue. But the fix is easy on utube if you have any computer skills at all or you know a teenager somewhere. And as always, with this item I will accept any returns no questions asked.