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