supply of supply of plastic cover of 4 aspect signal unit cover.supply of plastic cover of 4 aspect signal unit cover.,supply of plastic cover of 4 aspect signal unit cover operated from front side & bottom side made of black polythene sheet of 100 micron thickness size of 1700mm x 460mm x 205mm and back side 75mm wide corner to corner diagonal to be provided total up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front size and of 1.5 meter length at centre. [ warranty per iod: 30 months after the date of delivery ] ] , supply of plastic cover of 3 aspect signal unit cover operated from front & bottom side made of black polythene sheet of 100 micron thickness size of 1300mmx460mmx205mm and back side 75mm wi de corner to corner diagonal mark of silver colour of 100 micron thickness to be provided total up cover wit h signal unit suitable nylon rope of 5mm dia and 4 meter length to be provided on front size and of 1.5 met er length at centre. [ warranty period: 30 months after the date of delivery ] ] , supply of plastic cover of 2 aspect signal unit cover operated from front side & bottom side made of black polythene sheet of 100 micron thickness size of 1200mm x 460mm x 205mm and back side 75mm wide corner to corner diagonal to be provided total up cover with signal unit suitable nylon rope of 5 mm dia and 4 meter length to be provided on front size and of 1.5 meter length at centre. [ warranty per iod: 30 months after the date of delivery ] ] , plastic cover for route signal unit cover operated from front side of black polythene sheet o f 100 microne thickness size of 685mmx76mmx and back side 50mm corner to corner white diagonal mark of silver color of 100 micron. thickness to be provided with suitable nylone rope of 5mm dia and 1.5 mete r length. [ warranty period: 30 months after the date of delivery ] ]