240-pin DIMMs are used to provide DDR2 SDRAM memory for desktop computers. This 256mb 533Mhz PC2-4200 240-pin DIMM provides a 64-bit data path (72-bit for ECC or registered modules), so they are installed singly in 64-bit systems. Most DDR2 chipsets are expected to support dual-channel memory, effectively providing a 128-bit data path.

To use DDR2 memory, your system motherboard must have 240-pin DIMM slots and a DDR2-enabled chipset. DDR2 modules use a 1.8V power supply, providing a big power saving over the 2.5V DDR modules. The number of black components on a 240-pin DIMM may vary, but they always have 120 pins on the front and 120 pins on the back.