Corsair Apple Certified 16GB (2 x 8GB) DDR3 1333 MHz (PC3 10600) Laptop Memory for Mac Model CMSA16GX3M2A1333C9 Compatible with MacBook Pro (13-inch, Late 2011), MacBook Pro (13-inch, Early 2011), MacBook Pro (15-inch, Late 2011), MacBook Pro (15-inch, Early 2011), MacBook Pro (17-inch, Late 2011), MacBook Pro (17-inch, Early 2011) Density: 16GB (2x8GB SO-DIMM). No fan included Speed: 1333MHz CL9. Type : 204-Pin DDR3 SO-DIMM Timing: 9-9-9-24 (1333MHz) Pin Out: 204 Pin Voltage: 1.5V Limited Lifetime Warranty from Corsair. Memory Type: DDR3; Speed: 1333MHz