Aluminum C-Head Ground Clamp Serrated Jaw, Threaded Terminal. 5H Rated. HASTINGS 5H Rated Ground Sets require all components (Clamps, 4/0 Cable, Ferrules, Etc.) to be manufactured and assembled by HASTINGS. HASTINGS strictly will not recognize or approve a 5H Rating for any Ground Set(s) that are not manufactured and assembled by HASTINGS).