Kingston Technology ValueRAM 4 GB Kit of 2 (2x2 GB Modules) 1333MHz DDR3 PC3-10666 ECC CL9 DIMM Intel Certified (KVR13E9K2/4I) Kit of 2 2 GB modules of 1333MHz DDR3 Memory Specifically designed and tested for compatibility in various devices 240-Pin Unbuffered DIMM From the industry leader in PC Memory Backed by a lifetime warranty and free technical support Intel Certified