HP 404574-888 4GB 4 x 1GB PC2-6400U DDR2 800 Non-ECC Unbuffered Memory Kit Hynix Manufacturer: Hynix Memory Kit Manufacturer Part #: HYMP112U64CP8-S6 AB Memory Type: 240-Pin DDR2 SDRAM Capacity: 4GB 4 x 1GB Bus Type: PC2-6400U 800Mhz