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