This is a set of two DDR3 SDRAM memory modules from Elpida with a total capacity of 4 GB. Each module has a capacity of 2 GB and a bus speed of PC3-8500S. The memory modules are unbuffered and compatible with Sony laptops. They have been upgraded to improve the performance of your laptop. The modules were manufactured in Taiwan. The memory modules are suitable for use in various computer components and parts, including RAM. They are an essential component for upgrading your laptop's performance and speed. They are compatible with a wide range of laptops and offer a reliable and efficient performance.