This logic board includes an Intel 2.8GHz i5 (i5-5575R) processor, 16GB onboard memory and heatsink attached. Versions of this board exist with and without SSD connector, but this particular board does not include the PCIe SSD connector for installation of Apple's proprietary blade SSDs. The Late 2015 iMac 21.5" was available with multiple CPU and display options, but this board is only compatible with iMacs that have a standard 1920x1080 display and 2.8GHz i5 CPU.
661-02983 Logic Board 2.8GHz (16GB) – HDD for iMac 21.5-inch Late 2015 A1418 MK442LL/A, MK442LL/A (820-00431-A) This is a replacement logic board for the Late 2015 iMac 21.5" non-Retina models that come with a hard disk drive.