Kingston Technology Hyper X 4GB 1866MHz DDR3 Non-ECC CL9 DIMM (Kit of 2) XMP T1 Series KHX1866C9D3T1K2/4GX 4GB Kit (2x2GB modules) of DDR3 Desktop 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 Unbuffered 1866MHz CL9 240-pin DIMM type