{TAIL ~ The casing body} may be provided on both sides thereof with reliefs which serve to prevent the holding members from interfering with {HEAD ~ movement} of the slider 
{ TAIL ~ The casing body } may be provided on both sides thereof with reliefs which serve to prevent the holding members from interfering with { HEAD ~ movement } of the slider
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH