Plastic cover 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 mark of silver colour of 100 micron thickness to be provided total up cover with signal unit suitable nylon rope of 5mm dia and 4 metre length to be provided on front size and of 1. 5 metre length at center.