HP 647907-B212 COMP 4GB DDR3-1333MHZ ECC CL9 DRX8 UDIMMAddOn 4GB DDR3 SDRAM Memory Module 4 GB (1 x 4GB) DDR3 1333 PC3 10666 DDR3 SDRAM 1333 MHz Dual rank Memory CL9 1. 35 V ECC Unbuffered 240 pin DIMM Lifetime Warranty VPN: 647907 B212 AM SKU: RSC464126 UPC: 195285045874 4 GB memory allows you to have more programs open at a time Up to 1333 MHz memory speed with Unbuffered signal to manage your routine softwares with pace and accuracy DDR3 SDRAM interface multiplexes 2 bit data from memory cell and I O