I prefer to employ a shorter LES because placing a limitation on {HEAD ~ its travel} allows {TAIL ~ variations} in its length to control the angular relationship between the pleating elements and the main blade 
allows
I prefer to employ a shorter LES because placing a limitation on { HEAD ~ its travel } allows { TAIL ~ variations } in its length to control the angular relationship between the pleating elements and the main blade
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH