The Crucial 2GB RAM Desktop Memory DDR2 PC2-4200 is a set of two unbuffered DDR2 SDRAM modules, each with a capacity of 1GB. The memory units have a total capacity of 2GB and are designed for desktop computers. With a bus speed of PC2-4200 (DDR2-533) and 240 pins, these modules are reliable and high-performing. The Crucial brand ensures quality and durability, backed by a lifetime manufacturer warranty, making it a safe and secure choice for upgrading your computer's memory capacity.