The ProMOS 512MB DDR 333MHz PC2700U Desktop RAM consists of two SO-DIMM modules, each with a capacity of 256MB, providing a total capacity of 512MB. Made in the United States, this memory module is designed for desktop computers and operates at a bus speed of PC-2700 (DDR-333). With reliable performance and quality construction, this RAM upgrade is a great option for enhancing the speed and efficiency of your computer system.