SanDisk Ultra SDHC - Class 6 20MB/s ?

I just bought 2 16GB SDHC cards from a reputable dealer.  The documentation with the cards and the cards themselves have them as SanDisk Ultra SDHC Card with Class 6 and 20MB/s. 

The specs on the SanDisk product pages say that SanDisk Ultra SDHC are only Class 4 and 15MB/s.

Why is there a difference in the specifications?  Is it possible I have bought a fake?

By the way, this is the packaging:

I’m not sure how to interperet the lack of response.

@atj wrote:

I’m not sure how to interperet the lack of response.

By assuming that no one who has read your query has an answer or reponse?

If you’re looking to verify authenticity on these cards or have questions on conflicting specs, you should call SanDisk directly. This is a user’s forum. The folks at Sandisk are more qualified to address your concerns than most of the people here.

I am based in Australia.  SanDisk do not have an office in Australia that I can call.  I have already emailed SanDisk and they have not replied.

I was hoping someone here could tell me if SanDisk sell a Class 6 20MB/s card labelled as Ultra.  I guess the answer is no.

Australia   
1 800 262 504
M-F | 8am - 6pm New South Wales Time

Thanks.

I wonder why that number is not listed here: http://www.sandisk.com/about-sandisk/contact-us or here: http://www.sandisk.com/about-sandisk/worldwide-locations

Maybe because you didn’t click the top link on the main Contact Us page entitled Technical Support?

That where I got it.

So… did you get an answer, OP? I’d like to know this as well. I can’t seem to find any Ultra Class 6 cards in 16GB, yet people everywhere else seem to be able to. Like here: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6826&p=86421

I can only find Class 2 and Class 4 cards. Also, this card seems to have several different serial numbers.

SDSDH-016G-U46
SDSDH-016G-E11
SDSDH-016G-E12
SDSDH-016G-J95
SDSDH-016G-J61
SDSDH-016G-A11

Does anyone know what the difference between these are?