Product Detail 240-pin DIMMs are used to provide DDR2 SDRAM memory for desktop computers To use DDR2 memory, your system motherboard must have 240-pin DIMM slots and a DDR2-enabled chipset Form Factor - 240-pin DIMM Storage Capacity - 4GB Memory Speed -- 667MHz DDR2-667/PC2-5300 . The "Crucial CT2KIT25664AA667 4GB 2GBx2 240-pin DIMM DDR2 PC2-5300 Memory Module" is best product for you. We recommended Crucial CT2KIT25664AA667 4GB 2GBx2 240-pin DIMM DDR2 PC2-5300 Memory Module