Use models with Type 3R (NEMA) / IP43 enclosures for indoor or outdoor applications where they are protected from weather and splashing water. Use these models with pipes that carry fluids at temperatures in the range of -20°F to 250°F (-29°C to 121°C). A drain hole provides for you to use Type 3R (NEMA) models in applications where the fluid temperature is below the ambient dew point temperature. The drain hole knockout is plugged on IP43 models to prevent the intrusion of objects 0.04 in. (1 mm) in diameter and greater. If you remove the plug, you reduce the enclosure rating to IP23, which facilitates you to use these models in applications where the fluid temperature is below the ambient dew point temperature. Do not use these models in applications or environments where the temperature may cause the fluid to freeze.