AIR BRAKE HOSE COUPLING FOR BRAKE PIPE TO RDSO DRG NO. SK- 73547, ALT- 14 OR LATEST, MATERIAL AND SPECIFICATION CONFORMING TO RDSO ' S SPECIFICATION NO 02- ABR- 02, AMENDMENT NO 4 OF SEPTEMBER 2016 OR LATEST AND APPENDIX- F ( FIRM ` s TO SUBMIT OFFER WITH LATEST RDSO DRAWING & SPECIFICATION )