When cocked, the hook rest on the bottom edge of a small hole drilled in {HEAD ~ a lower corner} of {TAIL ~ a hooded type mailbox door} 
When cocked , the hook rest on the bottom edge of a small hole drilled in { HEAD ~ a lower corner } of { TAIL ~ a hooded type mailbox door }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL