In this construction, {TAIL ~ the sampler} 1″ includes {HEAD ~ a top ply} 3″ and a bottom ply 5″ having upper and lower surfaces 3 a″,5 a″ and 3 b″, 5 b″, respectively 
In this construction , { TAIL ~ the sampler } 1″ includes { HEAD ~ a top ply } 3″ and a bottom ply 5″ having upper and lower surfaces 3 a″,5 a″ and 3 b″ , 5 b″ , respectively
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH