Check out the buying guide in videos section ADATA continues to lead the industry in DRAM timing and density with these 4GB Premier Series DDR3L 1600 single piece memory modules The Premier Series 1600 Mbps DDR3L 240-Pin (Unbuffered DIMM) are standard pin design modules operating at 1.35 volts, with transmission bandwidth up to 12.8 Gb/second (PC3L 12800) Imultaneously ensuring compatibility with all the computer systems adopting the same standard and ecologically sound product