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The drivers that are built into OSx would be specifically for their Apple version. Unless you enjoy driver hell I'd stick with the Apple version.
 
I have a generic one from CompUSA and it works great. Just make sure it's mac compatible when you buy it.
 
I was going to buy a 3rd party adaptor because I figured it would be cheaper. I found them to be around the same price, some were a few bucks more others a couple dollars less. The $2-$5 savings on the cheaper ones wasn't really worth my time to return it and buy another should it not have functioned properly. If you already have one then it's worth trying. If not, I'd just buy the Apple one and be done with it.
 
I have one from Kensington , it was $15 or so shipping included. It works fine.
 
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