supply of master telephone unit with voice logging facility for lc gate telephone system,gate telephone (slave telephone) & others...etcmaster telephone unit with voice logging facility for lc gate telephone system,gate telephone (slave telephone) & others...etc,master telephone unit with voice logging facility for lc gate telephone system as per rdso specn. no. rdso/spn/tc/51/2011 rev.1 or latest. [ warranty period: 30 months after the date of delivery ] ] , gate telephone (slave telephone) unit for electronic lc gate telephone system as per rdso spn tc 51/2011 rev 1.0 or latest [ warranty period: 30 months after the date of deliver y ] ] , power supply system with mf battery of 12v/24v dc (12v dc supply shall be connected to t he station telephone unit & 24v shall be fed to line circuit) with maintenance free battery for electronic l c gate telephone system [ warranty period: 30 months after the date of delivery ] ] => limited