The core of the Camco Heated Drinking Water Hose is an NSF 61-certified, drinking water-safe hose that is BPA-, phthalate- and lead-free. The heated drinking water hose won't leach harmful chemicals into your water or leave it tasting like plastic the way standard garden hoses do. It is ideal for RVs, livestock, agriculture, kennels and other industrial, commercial and residential uses. Providing water line freeze protection down to -20 degrees F (-28 degrees C), the energy-saving thermostat only heats as needed, saving you money on your electric bill. The internal diameter of the hose is 5/8-inch, and the fittings are heavy-duty machined and plated for maximum corrosion resistance.