supply of supply of 4 wire spt for ibssupply of 4 wire spt for ibs,supply of 4 wire spt for ibs suitable for ofc communcation. each set shall comp rise one no of signal post telephone (spt) master unit (installed in sms office) alone with o ne no. of slave unit(which shall be installed on ibs post).both master and slave must work on 24v dc and must be suitable for (25kvac re area. it shall work on ofc . approval of sampl e material should be taken from consignee before bulk supply. material should be supply at consignee depot sse/s/m/jbp. this item is not available in gem. [ warranty period: 30 months afte r the date of delivery ] ]