4GB, 240-pin DIMM, DDR3 PC3-10600U,Dual rank, NON ECC ram memory module by Hynix (HMT351U6CFR8C-H9) Module Size:4GB Package:240-pin DIMM Feature:DDR3 PC3-10600 Specs:DDR3 PC3-10600 , CL=9 , Unbuffered , NON-ECC , DDR3-1333 , 1.5V , 512Meg x 64