OWC 32GB (2x16GB) PC3-12800 DDR3 1600MHz SO-DIMM 204 Pin CL11 Memory Upgrade Kit Compatible with 2015 iMac (OWC1600DDR3S32P) at Amazon.com
Kingston Technology 32GB (1 X 32GB) 1066MHz DDR3 240-Pin Quad Rank Registered ECC Low Voltage DIMM for HP Servers (PC3 8500) KTH-PL310QLV/32G at Amazon.com
Hynix HMT84GL7AMR4C-RD 32GB DDR3-1866 PC3-14900L 4Rx4 ECC Server Memory Module