"Caution - Men Working" Folding Floor Sign By SmartSign | 25" x 12" Plastic DURABLE PLASTIC. Signs are injection molded and outlast lightweight or corrugated competitive folding signs. EASE OF USE. Signs have a handle cut out for easy carrying and storage. GREAT VISIBILITY. Signs are double-sided for optimum visibility and are ideal for marking temporary hazards or displaying vital messages in any facility, building, warehouse, etc.