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