Apple iMac MK442LL/A 21.5-Inch Desktop (Discontinued by Manufacturer) 2.8GHz quad-core Intel Core i5 Turbo Boost up to 3.3GHz 8GB Onboard Memory (Configurable to 16GB) 1TB (5400-rpm) Hard Drive Intel Iris Pro Graphics 6200 21.5" LED-backlit IPS Display 1920 x 1080 Resolution 2.8 GHz Intel Core i5 8GB of 1867 MHz LPDDR3 Onboard Memory 1TB 5400 rpm Hard Drive Intel Iris Pro Graphics 6200 802.11ac Wi-Fi, Bluetooth 4.0 2x Thunderbolt 2 and 4x USB 3.0 Ports FaceTime HD Camera, Dual Mics, Speakers Mac OS X El Capitan