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