HP 500672-B21 COMP 4GB DDR3-1333MHZ ECC 1.5V DR UDIMMAddOn 4 GB DDR3 SDRAM Memory Module For Server 4 GB (1 x 4GB) DDR3 1333 PC3 10600 DDR3 SDRAM 1333 MHz Dual rank Memory CL9 1. 50 V ECC Unbuffered 240 pin UDIMM Lifetime Warranty VPN: 500672 B21 AM SKU: RSC204442 UPC: 821455560099 UDIMM 4 GB of memory to heighten your computer's performance 1333 MHz speed and Unbuffered signal to execute routine softwares at a steady pace DDR3 SDRAM interface multiplexes 2 bit data from memory cell and I O buses to