Hynix 16GB PC3-12800 DDR3 1600MHz ECC Registered Server Memory 240-Pin Dual Rank Model HMT42GR7MFR4C-PB at Amazon.com
Amazon.com: Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3L 1600MHz for Mac Book Pro(Early/Late 2011,Mid 2012), iMac(Mid 2011,Late 2012,Early/Late 2013,Late 2014,Mid 2015), Mac Mini(Mid 2011,Late 2012) MAC RAM : Electronics
HP Compaq 16GB DDR3 SDRAM Memory Module 16 DDR3 1333 (PC3 10600) 627808-B21 at Amazon.com
Kingston Technology 16GB 1600MHz DDR3 ECC Reg CL11 DIMM 2Rx4 Server Premier Memory KVR16R11D4/16HB at Amazon.com