{HEAD ~ Each} of the inside surfaces of the two external washers comprise {TAIL ~ an actuation plane} corresponding to one of the associated lateral retaining elements 
comprise
{ HEAD ~ Each } of the inside surfaces of the two external washers comprise { TAIL ~ an actuation plane } corresponding to one of the associated lateral retaining elements
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH