Upper shell portion A is threaded onto {HEAD ~ lower shell portion C} to form {TAIL ~ an airtight egg shaped container} except for opening 3 
Upper shell portion A is threaded onto { HEAD ~ lower shell portion C } to form { TAIL ~ an airtight egg shaped container } except for opening 3
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH