supply of 1) plastic cover for 4 aspect signal unit cover opened from front side and bottom side and made of black polythene sheet of 100 micron thickness size : 1700 mm x 460 mm x 205 mm. on back side 75 mm wide corner to corner diagonal cross mark of silver color of 100 micron thickness to be provided tie up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front side and of 1.5 mtr length at centre the sample must be approved before bulk supply. 2) plastic cover for 3 aspect signal unit cover opened from front side and bottom side and made of black polythene sheet of 100 micron thickness size : 1300 mm x 460 mm x 205 mm. on back side 75 mm wide corner to corner diagonal cross mark of silver color of 100 micron thickness to be provided tie up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front side and of 1.5 mtr length at centre. the sample must be approved before bulk supply..1) plastic cover for 4 aspect signal unit cover opened from front side and bottom side and made of black polythene sheet of 100 micron thickness size : 1700 mm x 460 mm x 205 mm. on back side 75 mm wide corner to corner diagonal cross mark of silver color of 100 micron thickness to be provided tie up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front side and of 1.5 mtr length at centre the sample must be approved before bulk supply. 2) plastic cover for 3 aspect signal unit cover opened from front side and bottom side and made of black polythene sheet of 100 micron thickness size : 1300 mm x 460 mm x 205 mm. on back side 75 mm wide corner to corner diagonal cross mark of silver color of 100 micron thickness to be provided tie up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front side and of 1.5 mtr length at centre. the sample must be approved before bulk supply..,plastic cover for 3 aspect signal unit cover op