Aquatic Technology 6910WS1206E 12"x6" Black Keep Closed Sign measures 12 x 06 inches, is printed on .040 mil Styrene Plastic and is designed to prevent a gate or door from being left open. Lettering height on this sign meets the state code for California. Our general information signs are very noticeable and used to inform people of facility restrictions, policy, object location or instruction. This sign is lightweight, durable, and waterproof for indoor or outdoor use.