Apple iMac MK452LL/A 21.5-Inch Retina 4K Desktop (Discontinued by Manufacturer) 3.1GHz quad-core Intel Core i5 Turbo Boost up to 3.6GHz 8GB Onboard Memory (Configurable to 16GB) 1TB (5400-rpm) Hard Drive Intel Iris Pro Graphics 6200 21.5" Retina 4K Display 4096 x 2304 Resolution 3.1 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