RAM for Dell Inspiron n5030

Hi all,

I have a DELL Inspiron N5030 which has served me for years and is still okay. I'm thinking of upgrading the RAM as it's become slow of late. Having read a few other topics on the board, I need some advice on the best way to get this done.  It says maximum RAM is 6GB, and it also seems to talk about two card slots. Does this mean a the total RAM from both cards should be 6GB or can I put 6GB in both. Also, I found this on a site, will this be okay?  I changed the keyboard and screen a while back, and so I can navigate myself around. 

DGB (2 X 4GB) 2RX8 PC3-10600S DDR3 1333MHz SODIMM CL9 204 Pin 1.5v Notebook Non-ECC, Unbuffered Laptop Memory RAM Compatible with Intel AMD and Mac Computer