General CDS Contract information:

The CDS contracts between the SPV can be $US500 million to $US1 billion, or sometimes more.
They have a variety of twists and turns, but it usually goes something like this:
if seven of the 100 reference entities default, the SPV has to pay the bank a third of the money;
if eight default, it’s two-thirds; and if nine default, the whole amount is repayable.

Every CDS contract varies in details in terms of the default event's impact to the principal loss.

You can read the full article in the link below:
http://www.businessspectator.com.au/bs.nsf/Article/A-tsunami-of-hope-or-terror-LHRJP?OpenDocument&src=spb