The casing body may be provided at {HEAD ~ each} of both sides thereof with {TAIL ~ a relief} which prevents the holding or grasping means from interfering with sliding movement of the slider when the same is slided 
with
The casing body may be provided at { HEAD ~ each } of both sides thereof with { TAIL ~ a relief } which prevents the holding or grasping means from interfering with sliding movement of the slider when the same is slided
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL 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 OTH