tender for cut off angle cock with vent (for air brake wagons) to rdsos drg. no. wd-88123-s-01, alt. no. 2(two), item no. 1 to 13 and rdsos specn. no. 02-abr-02, with amendment no.3 of april.10 & amendmentno.4 of sept.2016 appendix-d. mat. & spec. as per drg.