Supply of universal lamp proving relay ac miniature, plug-in contacts 4f-4b metal to carbon, as per rdso specn. no. sts/e/relays/ac lit led signal/09-2002 : irs:s23:rs:s34 and spec. no. brs:940,941a (common for main subsidiary signals) and technical specifications, for 110v dc/12w led signal of main all aspect, calling-on, route and shunt signals, complete with plug board, base, retaining clip and connecto