The Cleveland HB Turbo irons have a full hollow construction to maximize launch and ball speed over the HB. The high ball speeds can be seen across the face for maximal forgiveness. The HB are hybrid-like irons signed for improved forgiveness, higher ball flight, and straighter shots. , The Difference between the Cleveland HB and HB Turbo Irons is the Turbo charged face. the HB(hybrid) turbo offers a thinner face for shots to come off faster. , The Cleveland HB irons are a slightly smaller head than the Turbo irons. The Turbo set is meant to be an ultra game improvement iron for players with very slow swing speeds.