In one embodiment, the corrugation have a pitch of five inches and a height of one half inch; in another embodiment, the pitch is six inches and {HEAD ~ the height} is {TAIL ~ one inch} 
In one embodiment , the corrugation have a pitch of five inches and a height of one half inch ; in another embodiment , the pitch is six inches and { HEAD ~ the height } is { TAIL ~ one inch }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL