The base 12 defines {TAIL ~ four fastener holes} 19 in the bottom surface 18 thereof engaging {HEAD ~ the posts} 20 
The base 12 defines { TAIL ~ four fastener holes } 19 in the bottom surface 18 thereof engaging { HEAD ~ the posts } 20
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH