{HEAD ~ The bellows} has {TAIL ~ undulations} with ridges and valleys with ridge angles determined such that contact between adjacent undulations when the boot is operatively connected is confined to a plane 
has
{ HEAD ~ The bellows } has { TAIL ~ undulations } with ridges and valleys with ridge angles determined such that contact between adjacent undulations when the boot is operatively connected is confined to a plane
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH