Available in four materials, the "Do Not Enter" caution sign is best used for both indoors and outdoors since it is moisture-proof, UV-resistant, and weather-resistant. It also has high reduction from corrosion, so you're assured that this safety sign is durable and can withstand for a long period of time in a harsh environment. Two pre-drilled mounting holes and rounded corners can be seen on the topmost part of the sign. Caution sign Materials: aluminum, plastic, fiberglass, adhesive vinyl Aluminum: corrosion-proof and UV-resistant Plastic: moisture and weather-resistant Fiberglass: resistant to chemicals, weather, mold, mildew, stains Adhesive vinyl: weather, moisture, corrosion-resistant Indoor and outdoor use Pre-drilled mounting holes Radius corners Adhesive backing for adhesive vinyl Sizes: 3"x5" to 14"x20"