21.5″ APPLE IMAC 2009 – 2011 OS X 10.13
The 21.5″ iMac was released in 2009 and has 2 revisions the 2009 – 2011 models are and amazing revolutionary design from the previous 20″ Apple iMac. The 2012 to current models are the Razor thin design and to me almost unbelievable how you can get a whole computer into such a thin machine. The iMac has always been cutting egde design from the very first model released in 1998. These models still come with the Optical drive so if you are someone who likes to still use CDs and DVDs you would need one of these. The maximum OS you can go up to is OS X High Sierra 10.13.