SUN 511-1152 COMP 4GB DDR2-667MHZ ECC 1.8V DR FBDIMMAddOn 4 GB DDR2 SDRAM Memory Module For Server 4 GB (1 x 4GB) DDR2 667 DDR2 SDRAM 667 MHz Dual rank Memory CL5 1. 80 V ECC Fully Buffered 240 pin DIMM Lifetime Warranty VPN: 511 1152 AM SKU: RSC332211 UPC: 821455544556 4 GB memory allows you to have more programs open at a time Up to 667 MHz memory speed with CL5 latency to manage your routine softwares with pace and accuracy 240 pin pin DDR2 SDRAM interface synchronizes electrical and clock signals