Apple iMac A1418 21.5" (Late-2015) i5-5575R 2.8GHz, 1TB HDD, 8GB RAM MK442LL/A

Specs at a Glance:

• 21.5" 1920x1080 LED-backlit 16:9 widescreen IPS display
• Intel Core i5 2.8GHz quad-core "Broadwell" processor
• 8GB DDR3 RAM
• 1TB Hard Drive
• Intel Iris Pro 6200 graphics processor
• FaceTime HD Camera
• Four USB 3, two Thunderbolt and Gigabit Ethernet
• Wi-Fi 802.11ac (802.11a/b/g/n compatible) and Bluetooth 4.0
• macOS 10.13 High Sierra
• Apple Wireless Keyboard and Magic Mouse

More spec details below, courtesy of our friends at EveryMac.

The iMac "Core i5" 2.8 21.5-Inch Aluminum (Late 2015/Broadwell) features a 14-nm "Broadwell" Quad Core 2.8 GHz Intel "Core i5" processor (5575R) with four independent processor "cores" on a single chip, a 4 MB shared level 3 cache, 8 GB of onboard 1867 MHz LPDDR3 SDRAM (which could be upgraded to 16 GB at the time of order, but cannot be upgraded after system purchase at all), a 1 TB (5400 RPM) hard drive, and an "integrated" Intel Iris Pro 6200 graphics processor that shares system memory. It also has a built-in "FaceTime HD" webcam and stereo speakers.

This model has a 21.5" 1920x1080 LED-backlit 16:9 widescreen IPS display with a fully laminated glass cover and an anti-reflective coating. The rear of the case is aluminum and is thicker in the middle and tapers to a razor thin 5 mm at the edges.

Connectivity includes four USB 3.0 ports, dual Thunderbolt 2 ports, Gigabit Ethernet, 802.11ac Wi-Fi (802.11a/b/g/n compatible), and Bluetooth 4.0.

Compared to its predecessor, this model essentially has the same external enclosure, but it has a more advanced architecture and graphics architecture.