That's what I was thinking also.Actually Dale it depends on what year the bow is. A 2010 Z7 can not take the 2011 Z7X cam, but all the 2011 Z7's, (extreme, Magnum, and regular) all have the same cam. the only 2011 Z series bows that can not use the 2011 ZX cam are the EZ7 and the Z9