Acronym for Interchangeable Head, a feature of the 21C new style blister carded figure Figures in this budget-priced series have a redesigned neck post which offers restricted articulation (head tilts up and down but not side to side) but allows the heads to be easily removed and swapped with other heads of the same series (Note that the IH neck posts and heads are not compatible with any older SAM or SS figures or heads ) In addition, the figure has new GI Joe-style hands with bendable fingers which are interchangeable with older style hands