There is {HEAD ~ a cover} which closes {TAIL ~ the end} of the projection remote from the rim 
closes
There is { HEAD ~ a cover } which closes { TAIL ~ the end } of the projection remote from the rim
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH