Kingston HyperX Genesis 4GB Kit (2x2GB Modules) 800MHz DDR2 SODIMM Notebook Memory KHX6400S2LLK2/4G 4GB Kit of 800MHz DDR2 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 notebook computers From the industry leader in PC memory Non-ECC Low-Latency 200-pin unbuffered SODIMM type