the macbook air has been updated over four times since the original release. the first revision introduced better performance, a bigger hard drive, and a mini displayport for peripheral monitors. the second update, introduced with the macbook pro series, featured a lower price, better performance, and a longer-lasting battery. it was revised a third time in october 2010 when the outside container was redesigned. at this time apple began selling another model with a smaller, 11.6-inch (29 cm) screen until 2019. the fourth update was released in july 2011. there have been other revisions in between, but in october 2018, there was a fifth revision to the macbook air, with a fingerprint scanner, a larger retina screen, and a backlit keyboard.