A waterproof cover covers {HEAD ~ the axial gap} and serves to suppress water from the outside from reaching {TAIL ~ the bearing} 
A waterproof cover covers { HEAD ~ the axial gap } and serves to suppress water from the outside from reaching { TAIL ~ the bearing }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL