supply of supply of plastic cover for 4-aspect , supply of plastic cover for 4-aspect signal unit cover is opened from front side and bottom si de and made of black polythene sheet of 100 micron thickness , size 1700 mm x 460 mm x205 mm. on bac k side 75 mm wide corner to corner diagonal cross mark of white colour of 100 micron thickness to be provi ded. to tie up cover signal unit suitable nylon rope of 5 mm dia and 4 mtrs length to be provided on front si de and of 1.5 mtrs length at centre. [ warranty period: 30 months after the date of delivery ] ] , supply of plastic cover for 2 aspect signal unit cover opened from front side and bottom side and made of black polythene sheet of 100 micron thickness of size : 1200mm x 460mm x 205mm. on back side 75 mm wide corner to corner diagonal cross mark of white colour of 100 micron thickness to be provid ed. tie up cover with signal unit suitable nylon rope (black color) of 5mm dia and 4 meter length to be pro vided on front side & of 1.5 mtr length at centre. [ warranty period: 30 months after the date of delivery ] ] , supply of 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 si de 75 mm wide corner to corner diagonal cross mark of white colour of 100 micron thickness to be provide d. to tie up cover with signal unit suitable nylon rope (black colour) of 5 mm dia and 4 meter length to be p rovided on front side and of 1.5 mtr length at centre. [ warranty period: 30 months after the date of deliv ery ] ]