Aquatic Technology 5350WS2418E 24"x18" Red/White Danger Gaseous Oxidizer Sign is printed on .040 mil Styrene Plastic with 4 inch lettering and can be customized with a specific chemical or you can leave it blank. This sign is designed for safety reasons to be posted in your pool chemical room. Our danger signs indicate an immediately hazardous situation which, if not avoided, could result in serious illness. This is a lightweight, durable, and waterproof for indoor or outdoor use.