OWC 12GB (8GB+4GB) PC3-12800 DDR3L 1600MHz SO-DIMM 204 Pin CL11 Memory Upgrade Kit Compatible with iMac, Mac Mini, and MacBook Pro (OWC1600DDR3S12S) at Amazon.com
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4GB DDR3L Low Voltage 1600 MHz (PC3-12800) CL11 SODIMM - Notebook RAM | Dell USA