Deflectable medical devices

A deflectable medical device, comprising:

• a catheter shaft having a distal end;
• an ablation electrode disposed at the distal end;
• a deflection body including a longitudinally-extending spine and wherein a first group of slots are formed in the body and define a first group of ribs;
• a flex member disposed distal to the deflection body;
• an intermediate region disposed between the deflection body and the flex member, the intermediate region including a wall extending from the deflection body to the flex member, and an opening extending through the wall from an outer surface to an inner surface of the intermediate region;
• and
• a deflection mechanism coupled to the intermediate region, the deflection mechanism including a retaining portion and a pull wire portion,
• wherein the retaining portion comprises a collar configured to extend around at least a portion of the outer surface of the intermediate region.