{HEAD ~ A sealing and gripping element} for {TAIL ~ an expandable downhole tool} features a ring supporting a sealing material with radially extending rings into the sealing material during run in 
for
{ HEAD ~ A sealing and gripping element } for { TAIL ~ an expandable downhole tool } features a ring supporting a sealing material with radially extending rings into the sealing material during run in
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH