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