Komputerbay MACMEMORY 32GB (4x 8GB) PC3-12800 1600MHz SODIMM 204-Pin Laptop Memory 10-10-10-27 for Apple Mac Komputerbay MACMEMORY 32GB (4x 8GB) PC3-12800 1600MHz SODIMM 204-Pin Laptop Memory 10-10-10-27 for Apple Mac Certified Mac Memory Well Tested. Non-ECC Non parity Unbuffered Voltage 1.5V. Gold Leads. Supports Dual Channel We test every module before it leaves the building, and back all of our purchases up with a LIFETIME WARRANTY!  PC3-12800 (1600MHz)  DDR3 Laptop memory upgrade Non-ECC Non-Parity Unbuffered Density: 32GB (4x 8GB SO-DIMM) Timing: 10-10-10-27 (1600 MHz) Speed: 1600MHz CL10 Pin Out: 204 Pin Voltage: 1.5V Lifetime Warranty Limited Lifetime Scroll down to see compatible models. Please, make sure your Mac supports 8GB DDR3 1600MHz speed ram into one slot. Finding compatibility: On your Mac screen find and click Apple icon located in left hand side upper corner and chose " About this Mac ". Click " More info ". In the Contents section on the left side of the screen, click " Memory " See memory type and memory speed- MAKE SURE, YOURS IS DDR3, 1600MHz. Your Mac must support 8GB ram into one slot.