supply of ssbpac (digital) for single line as per rdso specification no. rdso/spn/175/ 2005 ver. 1 along with station master block panel along with dtmf based electronic block bell & block telephone equipment as per specification no rdso/spn/191/2005(ver. 0), microprocessor lighting & s urge protection devices for power line 24 dc class-c, lighting & surge protection devices for data lin e class-d, ekt for shunt key as per drg. no. sa-22601/alt.4 & irs: s-21/2001 and associated data cabl e including wired relay rack without relays. (required relays for this item will be supplied by railways) of make:- m/s efftronics system private limited. ]