Each protrusion is preferably positioned adjacent {HEAD ~ an inset} 22A or 22B, on {TAIL ~ the block top surface} 10 
on
Each protrusion is preferably positioned adjacent { HEAD ~ an inset } 22A or 22B , on { TAIL ~ the block top surface } 10
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH