HP 647901-S21 COMP 16GB DDR3-1333MHZ ECC CL9 DR RDIMMAddOn 16GB DDR3 SDRAM Memory Module For Server 16 GB (1 x 16GB) DDR3 1333 PC3 10664 DDR3 SDRAM 1333 MHz Dual rank Memory CL9 1. 35 V ECC Registered 240 pin DIMM Lifetime Warranty VPN: 647901 S21 AM SKU: RSC802752 UPC: 821455232255 16 GB of memory to maintain symmetry with processor and hard drive and bring out the ultimate computing experience Up to 1333 MHz memory speed to manage your routine softwares with pace and accuracy 240 pin pin DDR3 SDRAM