4GB Total memory using 2pc of 2GB PC2-5300 DDR2-667 CL5 16c 200p SDRAM SODIMM. Genuine CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS MAX MEMORY 4GB SOCKETS 2 64BIT OPERATING SYSTEM REQUIRED Features Compatible with Dell Vostro 1500