Kingston Technology HyperX 4 GB Kit (2x2GB Modules) 1333 (PC3 10666) 240-Pin DDR3 SDRAM KHX1333C9D3K2/4G 4GB Kit including two 2GB modules of 1333MHz Class 9 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 Low-Latency 240-pin unbuffered DIMM type