supply of electronic l.c. gate telephone system , power supply system with mf battery of12v/24v dc (12v dc supply shall be connected to th e station telephone unit & 24v shall be fed to line circuit) with maintenance free battery for electronic lc gate telephone system as per specification no. rdso/spn/tc-51/2011, rev 1.0 or latest including battery c harger [ warranty period: 30 months after the date of delivery ] ] , supply of master telephone unit with voice logging facility for electronic lc gate telephone s ystem as per specification no. rdso/spn/tc/51/2011 rev.1.0 or latest. [ warranty period: 30 months aft er the date of delivery ] ] , supply of gate telephone (slave telephones) for electronic lc gate telephone system as pe r specification no. rdso /spn/tc/51/2011 rev 1.0 or latest. [ warranty period: 30 months after the date of delivery ] ]