This Apple computer has been upgraded over the base Apple model by Apple in their factory. The base Apple computer model this upgraded model was built upon was MD213LL/A . The Apple upgrade specific to this model is: Processor upgraded from 2.5GHz dual-core Core i5 to 2.9GHz dual-core Core i7. If compare with MD212LL/A model you find additional upgrade of the Hard Drive from 128 GB to 256 GB. Excellent crisp Retina Display, Fast, Thin, Light it is perfect for travelers.