Kingston Technology HyperX 4 GB Kit (2x2 GB Modules) 4 Dual Channel Kit 2133 (PC3 17000) 240-Pin DDR3 SDRAM KHX2133C9AD3T1K2/4GX 4GB Kit including two 2GB modules of 2133MHz Class 9 XMP Tall Fin Profile 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