{TAIL ~ Preferably, the depth “DG}” of the race is equal to or greater than the length of {HEAD ~ the lip} of the largest cap to be opened 
{ TAIL ~ Preferably , the depth “ DG } ” of the race is equal to or greater than the length of { HEAD ~ the lip } of the largest cap to be opened
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH