You are welcome, you only have to look for the exact specs as in the link and buy any make you like, most preferably cheaper make, it's entirely up to you.
http://uk.crucial.com/gbr/en/aspire-r3-131t/CT7677073
Main specs: DDR3 PC3L-12800 1600MHz
voltage:1.35v
Unbuffered, Non-ECC