piercing at least two transversely spaced apertures in {HEAD ~ an elongated sheet} of {TAIL ~ heat conducting}, deformable material 
of
piercing at least two transversely spaced apertures in { HEAD ~ an elongated sheet } of { TAIL ~ heat conducting } , deformable material
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH