supply of electronic l.c. gate telephone system. , 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 ] ] , gate telephone (slave telephone) unit with surge protection & line connection unit of electronic lc gate telephone system as per specification no.: rdso /spn/tc -51/2021 rev.1.0 or latest (wit h voice logging facility) compatible with the existing electronic lc gate telephone system. [ warranty per iod: 30 months after the date of delivery ] ] , supply of centralized power supply system 24v dc power pack with 7ah mf battery for elect ronic lc gate telephone as per rdso specification no.rdso/spn/tc/51/2021 (rev 1.0) or latest. [ warrant y period: 30 months after the date of delivery ] ]