PISTON PACKING & WEAR RING FOR BRAKE CYLINDER 300 MM. ( i ) PISTON PACKING AS PER RDSO Drawing No. WD- 92051- S- 15 Alt- NIL Conforming to RDSO Spec. No. 02- ABR- 02 with Amendment No. 04 of Sept- 2016, Appendix- B ( ii ) WEAR RING AS PER RDSO Drawing No. WD- 92051- S- 14, Alt- 03 Conforming to RDSO Spec. No. 02- ABR- 02 with Amendment No. 04 of Sept- 2016, Appendix- L.