Municipal Supply and Sign Co. Slippery When Wet Sign - 18 x 18. A Real Sign. 10 Year 3M Warranty MUTCD COMPLIANT: This sign is designed to meet the Manual on Uniform Traffic Control Devices (MUTCD) specifications REFLECTIVE SHEETING: 3M Engineer Grade reflective sheeting ALODIZED ALUMINUM: Sign is Manufactured on D.O.T. Alodized Aluminum BEST PERFORMANCE: Our signs last 7-10 years in Florida UV and sunlight, are washable, completely recyclable, environment friendly Not for road use.