In {TAIL ~ preferred embodiments}, the pitch between corrugations may be five inches, with a depth of {HEAD ~ one half inch} 
In { TAIL ~ preferred embodiments } , the pitch between corrugations may be five inches , with a depth of { HEAD ~ one half inch }
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD