The Kingston 4 GB DDR2 2Rx8 PC2-6400 desktop memory kit includes two low-profile modules, each providing 2GB of capacity. This DDR2 SDRAM memory is designed for high performance at a bus speed of PC2-6400 (DDR2-800). With a total capacity of 4GB, this memory kit is ideal for upgrading or replacing existing memory modules in desktop computers for improved speed and multitasking capabilities. Built by Kingston, a trusted brand in memory technology, this module is a reliable choice for enhancing computer performance.