NMC Rigid plastic OSHA sign. OSHA signs are the perfect way to alert your employees and guests when a hazard is present in your facility. Keep your facility safe with an OSHA regulated sign. It prevent an accident. These OSHA signs comply with OSHA 29 CFR 1910.145. Mounting: yes. Good chemical resistance. Header "CAUTION" and legend "DRIVERS MUST CHOCK WHEELS ON BOTH SIDES". Maximum temperature: 183 degrees F. Measures 14-inches length by 10-inches height. 0.050 thick polystyrene material is ideal for long lasting indoor or outdoor use.