National Marker Company Sign with ?DANGER - ALL DRIVERS MUST CHOCK WHEELS? is specifically designed as a part of safety-measures that helps to instruct the drivers to chock their wheels and prevent accidental movement, therefore making the . The OSHA danger sign is manufactured using premium quality material that boosts the durability and has the ability to withstand extreme weather conditions. The clear, simple and bold text of the sign is noticeable easily, while the clear crystal coating helps increasing the visibility. Apart from this, Sign muscle protects from scratches, scuffing, pre-mature fading, and other environmental damage.