TerraCair ultrapure DEF improves fuel economy and reduces nitrogen oxide concentrations (pollutants) to ensure optimum performance of the SCR (Selective Catalytic Reduction) system. Made from high purity urea and deionized water. Meets EPA (Environmental Protection Agency) 2010 regulations. API (American Petroleum Institute) certified to meet the stringent AUS32, DIN70070 and ISO 22241 standards for purity and concentration. Flexible dispensing nozzle designed to fit diesel exhaust fluid vehicle fill port. Single use.