The position of {HEAD ~ the tray} is then secured with a fastener screwably extending through {TAIL ~ the second arm} into a friction fit relationship with the shelf 
The position of { HEAD ~ the tray } is then secured with a fastener screwably extending through { TAIL ~ the second arm } into a friction fit relationship with the shelf
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH