4GB DDR3-1600 ECC UDIMM FOR IBM # 00D4955Axiom Memory Axiom 4GB DDR3 1600 ECC UDIMM for IBM 00D4955, 00D4957, 00Y3653 4 GB DDR3 1600 PC3 12800 DDR3 SDRAM 1600 MHz ECC 240 pin UDIMM Lifetime Warranty VPN: 00D4955 AX SKU: RSC142423 UPC: 845282074338 4 GB of memory makes a perfect symmetry with your latest model processor and boosts up your computer's performance 1600 MHz memory speed for great multitasking capability DDR3 SDRAM interface synchronizes electrical and clock signals for an