supply of lock for h type tight lock coupler (frontier make)for high tensile tight lock center buffer coupler with aar h type head and balanced draft gear. matl. & spec. : rdso specification no. rdso/2011/cg-03, (rev.-3)lock for h type tight lock coupler (frontier make)for high tensile tight lock center buffer coupler with aar h type head and balanced draft gear. matl. & spec. : rdso specification no. rdso/2011/cg-03, (rev.-3),lock for h type tight lock coupler (frontier make)for high tensile tight lock center buffer couple r with aar h type head and balanced draft gear. matl. & spec. : rdso specification no. rdso/2011/cg-03, ( rev.-3) [ warranty period: 30 months after the date of delivery ]