supply of supply, installation, wiring, testing and commissioning of signal post telephone spt (half duplex) , supply, installation, wiring, testing and commissioning of signal post telephone spt (half dupl ex) at ibs location and adjacent station . (each set shall comprise one no. of signal post telephone spt) ma ster unit (which shall be installed on ibs post) along with one no. of slave unit to be installed in sm office su itable for working on 24v dc and suitable for 25kv re area as per instruction of site in charge ,aces make or similar. note: the contractor shall ensure that there is no interference in communication between the m aster and slave due to re induction. cable from ib signal unit to the cable termination board in sms room/ relay room will be provided railway [ warranty period: 30 months after the date of delivery ] ]