The product is a 2 pack of Nanya NT4GC64B8HG0NF-DI 4GB 2Rx8 PC3-12800U RAM modules. Each module has a capacity of 4GB, and the total capacity of the two modules is 8GB. These DDR3 SDRAM modules have a bus speed of PC3-12800U (DDR3-1600) and are designed in a DIMM form factor. Ideal for upgrading or replacing memory modules in computers, this 2 pack of RAM is compatible with Windows operating systems.