the second design element comprises {HEAD ~ a groove} recessed into {TAIL ~ the interior surface} of the body 
recessed into
the second design element comprises { HEAD ~ a groove } recessed into { TAIL ~ the interior surface } of the body
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH