procurement of relay, plug in type, styleprocurement of relay, plug in type, style, relay, plug in type, style ac-led all aspects, ac lamp proving relay unit with in- built current transformer type, slow release neutral line relay, 4f / 4b, contacts, front and back contacts, metal to carbon shall be suitable for working in series with the 110 volt ac, led signal lamp rated at 15 watt conforming to rdso spec. no. sts / e / relays / ac lit led signal / 09-2002, amdt.1 brs: 941a, irs: s- 34 and irs: s- 23 ( as applicable ) .the interlocking code for this unit shall be abdhk.