Kingston ValueRAM 4 GB 1333MHz DDR3 CL9 SO-DIMM Notebook Memory KVR1333D3S9/4GETR One 4GB modules of 1333MHz DDR3 Notebook Memory Specifically designed and tested for compatibility in various makes and models of notebook computers 204-pin unbuffered SODIMM From the industry leader in PC memory Backed by a lifetime warranty and free technical support