Super Spars mast heel/plug product (SS code HP4) with - 4 Sheaves Tenon. ( 4 plastic sheaves - Plain bearings). Fits Super Spar alloy masts only. On the Super spar heel plug are 3 very small protruding lugs on the sides and front, and depending on the section (M2, M7 etc) you may have to gently file one of more ‘lugs’ to make a snug fit to the Super Spar section in question.