Aquatic Technology 1309WS2418E 18" x 24" Nebraska Compliant No Lifeguard Warning Sign - This No Lifeguard Warning Sign is compliant with Nebraska state code. The sign measures 18" x 24" and is constructed of durable plastic. Its purpose is to warn children under the age of 16 to not use a pool or spa without adult supervision. It is designed to withstand harsh weather and swimming conditions.