The pins may be engaged into the notches of the base for securing {HEAD ~ the plate} at {TAIL ~ the vertical position} 
at
The pins may be engaged into the notches of the base for securing { HEAD ~ the plate } at { TAIL ~ the vertical position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL