Product Number: MD506LL/A 85 Watt Use an extra adapter for home or work. The Apple 85W MagSafe 2 Power Adapter is made specifically for your MacBook Pro with Retina display. Not sure if this is the right power adapter for your Mac? See this article for more details about choosing the right one. Knowing which specific Mac model you have is important. If you are running OS X Lion (10.7) or later go to the “” menu at the top left of your screen, choose “About this Mac” then click the “More Info...” button. Your Mac model and generation will be displayed. If you are running an earlier version of OS X, you can enter your serial number here to find out which model you have.