Used Micron 8GB (2x4GB) DDR3-1600 SODIMM ram memory
Specs:
Micron Memory
4GB per module
DDR3-1600
PC3-12800
204 pin SODIMM
Non ECC
1.35v
Fits:
Apple iMac 27″ Late 2012
Apple iMac 27″ Late 2013
Apple iMac 27″ 5k Late 2014
Apple iMac 27″ 5k Mid 2015
MT16JTF51264JHZ-1G6M2 Micron 4GB PC3-12800 DDR3-1600MHz non-ECC Unbuffered CL11 204-Pin SoDimm 1.35V Low Voltage Single Rank Memory Module