tender for cut off angle cock with vent [complete] for air brake wagons to rdsos drg. no. wd-88123/s-01,alt. no. 2 [two] or latest and rdsos drg. no. wd-88123/s-02, alt. no. 6 [six] or latest. to rdso specn. no.02-abr- 02 with amendment no. 4 of sept. 2016 or latest. this item is reserved forprocurement from rdso approved sources only.