NIS 2011 subscription duration

I have just purchased a box of NIS 2011 for 1 PC with 2 years subscription from a retail shop in Hong Kong.  This box is different from the one I purchased before.  On the box itself, it said "1 Year Protection for 1 PC" but there is a sticker which says "Special 2PC Version".  However, the shopkeeper emphasized that I can use it for 2 years' protection repeatedly.  The price of this box of NIS2011 is same as the one I bought before.

 

1.  Is this a genuine 2-year subscription?

2.  If yes, do I need to reinstall or re-enter any product key after the 1-year protection?

3.  I have not opened the box yet, so I don't know the contents.  That's why I have this question - if there is no 2nd key inside the box, how can I get the 2nd year's protection?

 

Can anyone help?

 

Thanks in advance.

dtse