Kingston HyperX 4 GB Kit (2x2 GB Modules) 1333 MHz DDR3 Desktop Memory KHX1333C7D3K2/4GX 4 GB kit of 1333MHz 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