supply of over hauling kit for duplex check valveover hauling kit for duplex check valve, over hauling kit for duplex check valve of m / s knorr-bremse make used in air spring suspension system of emu coaches, consisting of 4 ( four ) nos. items in set, conforming to rdsos spec. no.str-c-k-407 ( rev-03 ) , amendment-1 of sept 2018. to m / s. kbi drg. / spec. no. as item- ( 1 ) sealing ring, to m / s. kbi part no.-453890=02 nos / set, ( 2 ) o ring, to m / s. kbi part no.-a27763 / 26=02 nos / set, ( 3 ) toothed washer, to m / s. kbi part no.-466031=02 nos / set & ( 4 ) valve head, to m / s. kbi part no.-a48128=02 nos / set