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