LED- BASED LOCO SIGNAL EXCHANGE LIGHT ONE SET CONSISTS OF FOUR SETS OF LED LIGHTS ( RED AND GREEN ) AND FOUR NOs. OF OPERATING PANEL HAVING OPERATING VOLTAGE 110V DC +/- 22. 5 % AS PER RDSO MODIFICATION NO. RDSO/ 2018/ EL/ MS/ 0470, DATED: 18. 06. 2018 AND DRG NO. ALT- SES- L- 78, REV NO- 00 as well as DRG NO. ALT- SES- C- 77, REV NO. 00.