supply of 4 wire dtmf based way station equipment completes as per rdso specification no.irs.tc-60/93 , supply and installation of 4 wire dtmf based way station equipment completes as per rdso specification no.irs.tc-60/93 and 4 wire control telephone with audio visual indication and reset button fitte d on telephone conforming to specification no.irs tc-38/97 or latest. this work also includes supply and wiring of power supply arrangements for way station equipment conforming to specification irs.tc.72/97. o r latest [all the materials required for the work shall be supplied by the contractor]. [ warranty period: 30 months after the date of delivery ] ]