8GB Total. Two 4GB PC3-12800 204 pin SODIMM DDR3 1600MHz 

MANUFACTURED BY 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