Corsair TWIN2X- Why would 1 of 4 modules not have a manufacture date?

[Texas-Hansen]

I just installed four modules (2gb each for total of 8 gb) of Corsair TWIN2X4096-6400C5DHX RAM and 3 of the modules show the manufacturing date but the 4th module does not show the manufacture date. The reason I'm inquiring about it is that I understand that these are suppose to be matched pairs of modules but the lack of a manufacture date for one module makes me question if they are matched pairs or if something could be wrong with it such that is does not show. Any thoughts on this?

 

[XMSYellowbeard]

The date won't determine if it is a matched pair or not. It's the lot numbers and revisions that we use when matching modules. Are you having any stability issues?

 

[Texas-Hansen]

The date won't determine if it is a matched pair or not. It's the lot numbers and revisions that we use when matching modules. Are you having any stability issues?

Thanks. No stability issues. Very stable so far and ran memtest86+ for >20 hours. It was more of a curiosity and question to make sure this was not something that could create an issue down the road or somehow someone returned some RAM and inserted "fake" stuff in there that I got.

Thanks