supply of hole marking fixture & lock for improved high tensile tight lock centre buffer couplerhole marking fixture & lock for improved high tensile tight lock centre buffer coupler,hole marking fixture to sanrok drg. no. 1ed-4993 for tertiary pin arrangement with chain & l ock pin for sanrok make high tensile tight lock centre buffer coupler to rdso specification no. rdso/201 1/cg-03 rev.03. make- sanrok. [ warranty period: 30 months after the date of delivery ] ] , lock for improved high tensile tight lock centre buffer coupler with aar-h type head to r dso spec.no.rdso/2011/cg -03(rev.3) to sanrok drg.no.1ed-1069, [ warranty period: 30 months after the date of delivery ] ]