2(1)The slow moving vehicle sign to be attached to a farm tractor or self-propelled implement of husbandry and every vehicle designed for operation with speeds not in excess of forty kilometres per hour or any vehicle towed by them shall be in the shape of a base-down equilateral triangle, fluorescent yellow-orange in colour with a dark red retro-reflective border and shall be of the dimensions and size as prescribed and illustrated in the following figure: