supply of power supply system, master telephone unit & others.....etcpower supply system, master telephone unit & others.....etc,gate telephone (slave telephone) for electronic lc gate telephone system as pe r specification no. rdso spn tc 51/2011 rev 1.0 or latest. make: bentron or similar. [ warranty period: 30 months after the date of delivery ] ] , power supply system having both 12v/24v dc output including battery charger with minimu m 7ah, 24v dc mf battery. 12v dc supply shall be connected to the station telephone unit & 24v dc shall be fed to line circuit for lc gate telephone system as per specification no. rdso/spn/tc-51/2011, rev 1.0 or latest. make: bentron or similar. [ warranty period: 30 months after the date of delivery ] ] , master telephone unit with voice logging facility for electronic lc gate telephone system as per specification no. rdso/spn/tc/51/2011 rev 1.0 or latest. make: bentron or similar. [ warranty perio d: 30 months after the date of delivery ] ] => limited