The National Marker Company sign with the legend âCAUTION â WATCH YOUR HEADâ is often used in industrial facilities and construction sites to alert the visitors and workers about the low-ceilinged areas or protruding objects overhead. It helps in preventing any accidents and ensuring personnel safety. The sign shows the message in clear, bold font to ensure easy readability even from a distance, while the contrasting yellow and black colors quickly gain the attention. The caution signage has an NMC Sign Muscle coating to protect the text against fading, scratches, scuffing, mold, and moisture and complies with OSHA standard.