PC Memory: Are the following compatible? Kingston and corsair?

Question

VS2GB667D2

http://www.dabs.com/productview.aspx?Quicklinx=4FSK&CategorySelectedId=11150&PageMode=1&NavigationKey=11150,48820000,4294956039,11,48800000,4294963789#specifications

with

http://www.dabs.com/ProductList.aspx?SearchTerms=VS2GB667D2&SearchMode=All&SearchKey=All&PageMode=3&NavigationKey=0&SearchType=1

Answer 1

Mazuk is partly right. Same manufacture and specs. E.g clock speed etc. Today's memory is often dual channel and you are really wasting money if you mix them. Even none dual channel memory will run at the speed of the slowest stick you have. So paying extra for faster memory mixed with slower will not benefit from the extra speed.  

Answer 2

They are both DIMM DDR2 677Mhz  so there is not issue there however i would recommend using the same manufacturer just in case.

Answer 3

Are they DDR or DDR2

DDR is not capable with DDR2

I need more details to answer it