It may be {HEAD ~ an inner surface} of {TAIL ~ the casing} so long as the weighting means 22 is detachably arranged at the casing while being preferably exposed 
of
It may be { HEAD ~ an inner surface } of { TAIL ~ the casing } so long as the weighting means 22 is detachably arranged at the casing while being preferably exposed
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH