Wintec Value Mhzcl9 4Gb(2X2Gb) UDIMM Kit 1Rx8 4 Dual Channel Kit DDR3 1333 (PC3 10600) 240-pin SDRAM 3VH13339U8-4GK Storage Capacity: 4GB Technology: DDR3 SDRAM Form Factor: DIMM Compatibility: desktop 1333 MHz speed