The product is a 2-pack of Elpida 1GB 1RX8 PC2-6400U-666 desktop memory modules. These DIMM modules are ECC RAM, providing error correction for enhanced reliability. Each module has a total capacity of 1GB, with a bus speed of PC2-6400 (DDR2-800). Ideal for upgrading or replacing memory modules in desktop computers, these Elpida modules offer a solution for increasing system performance and capacity.