Each of the side surfaces has an inset spanning from {TAIL ~ the block top surface} to {HEAD ~ the block bottom surface} 
Each of the side surfaces has an inset spanning from { TAIL ~ the block top surface } to { HEAD ~ the block bottom surface }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD