4GB Total memory 1pcs of 4GB 240pin PC3-10600 CL9 16c 128x8 DDR3-1333 DIMM. Compatible with: HP Pavilion p6-2049, p6-2050a, p6-2052uk, p6-2053it Maximum Memory: 4GB with 32-bit OS 8GB with 64-bit OS Expansions: 2 Sockets