Kingston HyperX 4GB Kit 1600MHz DDR3 PC3-12800 Non-ECC CL9 XMP SODIMM Notebook Memory KHX16S9K2/4XR 4GB Kit (2x2GB) of DDR3 Non-ECC Notebook Memory Utilizes HyperX module with faster latency timing for higher performance and speed Specifically designed and tested for compatibility in various makes and models of desktop computers From the industry leader in PC memory Non-ECC 1600MHz 204-pin CL9 Unbuffered SODIMM Backed by a lifetime warranty and free technical support