<P> The product's second iteration, known as the "unibody" model, has a casing made from a single piece of aluminum . It debuted in October 2008 in 13 - and 15 - inch screen sizes . In January 2009, the 17 - inch model was updated with the same unibody design . Subsequent updates brought upgraded Intel Core i5 and i7 processors and introduced Intel's Thunderbolt technology . </P> <P> Apple released the third generation of MacBook Pro with a 15 - inch screen during WWDC 2012 and discontinued the 17 - inch variant . The previous generation 13 - and 15 - inch unibody models continued to sell with updated processors . The third generation model is thinner than its predecessor and is the first to include a high - resolution Retina Display . A 13 - inch variant was released in October 2012 . </P> <P> The fourth generation MacBook Pro was announced on October 27, 2016 . It replaces the function keys with an interactive, multi-touch "Touch Bar" and a Touch ID sensor integrated into the Power button . </P> <P> The original 15 - inch MacBook Pro was announced on January 10, 2006 by Steve Jobs at the Macworld Conference & Expo . The 17 - inch model was unveiled on April 24, 2006 . The first design was largely a carryover from the PowerBook G4, but uses Intel Core CPUs instead of PowerPC G4 chips . The 15 - inch MacBook Pro weighs the same as the 15 - inch aluminum PowerBook G4, but is 0.1 inches (0.25 cm) deeper, 0.4 inches (1.0 cm) wider, and 0.1 inches (0.25 cm) thinner . Other changes from the PowerBook include a built - in iSight webcam and the inclusion of MagSafe, a magnetic power connector designed to detach easily when yanked . These features were later brought over to the MacBook . The optical drive was reduced in size in order to fit into the slimmer MacBook Pro, hence it runs slower than the optical drive in the PowerBook G4 and cannot write to dual layer DVDs . </P>

When did the macbook touch bar come out