These are modules to 2GB each (so 2x2GB)
Identified by computer and motherboard.
There was a clear difference between 4gb I had before and now 8GB on the computer already quau Windows start anything.
The only downside that this is in the bios I saw my two strips tour 1333 MHz instead of 1600 MHz. Is this is due to my other 2 modules G.Skill NT Series 4GB (2x 2GB) DDR3 1333 MHz flanges Kingston 1333MHz? I do not know but it's the only negative that I found these strips.
At its I recommend this product, and Amazon impeccable delivery.