8GB Total. 2pcs 4GB PC3-12800 204 pin SODIMM DDR3 1600MHz Major brand memory. Brand Computer Memory Solutions We don't sell generic modules to avoid incompatibility
MAX MEMORY: 32GB SOCKETS 4
COMPATIBLE WITH: Apple iMac "Core i5" 3.3 27-Inch (Retina 5K, 2015) Mid-2015 - MF885LL/A - iMac15, 1 - A1419 - 2806