Full Details from Amazon.com : http://www.amazon.com/gp/product/B005JRH9TE?tag=onigi-20
Corsair Apple Certified 4GB (1x4GB) DDR3 1333 MHz (PC3 10666) Laptop Memory (CMSA4GX3M1A1333C9)
Capacity 1 x 4GB
Speed 1333MHz CL9
Timing 9-9-9-24 1333 MHz
Pin Out 204 Pin
Voltage 15V
Latency CAS 9
