I have the 34DD.  it needs 3 hooks in back like the 36DD has.  It's so stupid that it has only 2 hooks!  I had the 36DD but recently found out my bra size is really 34DD, so I ordered it in 34DD and SURPRISE!  It has only 2 hooks.  It's a great bra, great shape, great support, but not with 2 hooks.  With 3!