500GB HDD Pre-Loaded with Apple OS X El Capitan 10.11.6 operating system.  Hard drive will come already set up with all necessary drivers and applications, just plug n play.  Item Dimensions 3.94 x 2.75 x 0.37 inches Item Weight 3.49 ounces Ships same or next day with tracking! *This Hard Drive is compatible with MacBook Pros released mid 2007 - 2012* Thank you. 🍁🍁Ships to Canada for only $13🍁🍁 🌮🌮Ships to Mexico for only $13🌮🌮