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