Just ordered a HB 561 to use with my Minn Kota Terrova.  I looked on the HB web site for the correct adapter cable, and their long list of compatible sonar units that used adapter cable MKR-US2-8 did not include the 561.  It did include the HB 560.  I think the MKR-US2-8  is the correct adapter cable for my HB 561.  (want to get the right one the first time) Is this correct?  
thanks,  Fuzz