DEF - Diesel Exhaust Fluid
I was an executive of Cummins for 15 years. Left Cummins to work for two global companies at a senior executive level. I’m very familiar with DEF, it’s development (in the North America market, it had been used in Europe long before) and its limitations.
I would highly encourage you purchase DEF from a bulk tank in a truck source. Age, storage, heat and cold can affect DEF. product