New Logic Board (motherboard) and 1TB SSD Hard-drive fitted last year. No longer needed as upgraded. Has all been reset and macOS reinstalled and ready to go.

"Core i5" 2.7 21.5-Inch Aluminium (Late 2013/Haswell) features a Quad Core 2.7 GHz Intel "Core i5" (4570R) processor. 8 GB of 1600 MHz DDR3 SDRAM,

New 1TB SSD, and an "integrated" Intel Iris Pro 5200 graphics processor with 128 MB of embedded DRAM (and shared system memory). The "Late 2013" iMac models are shipped with a compact aluminium Apple Wireless Keyboard and a multi-touch "Magic Mouse,

https://everymac.com/systems/apple/imac/specs/imac-core-i5-2.7-21-inch-aluminum-late-2013-specs.html