Memory Question

I have a Gigabyte Motherboard model#GA-MA790X-DS4 and currently have 4GB Ram..the Ram is G-Skill DDR2 1066
PC2 8500 Do I need to get the same manufacturer or can I use a different manufacturer just as long as the it is 1066mhz and PC2 8500 240pin? I am wanting to add 2 More GB.

Thanks in advance,
JC