LENOVO 67Y2607 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: 67Y2607 AM SKU: RSC443688 UPC: 821455231623 4 GB memory allows you to have more programs open at a time UDIMM 4 GB of memory makes a perfect symmetry with your latest model processor and boosts up your computer's performance 1333 MHz speed and CL9 latency to execute