This listing is for 4 sticks of Samsung (x2) and ELPIDA (x2) 2GB 2Rx8 RAM Memory PC3-10600S-9-10-F1 SODIMM 204-pin computer memory ram.  Four sticks of ram included, two of each brand. 8 Gb of total ram if used together. Modules were used together in an iMac to total 8Gb ram. Common size for laptops as well.