Important Note: This item is not returnable Use the Urnex Single-Cup Brewer Cleaning & Descaling Kit to properly maintain your single-cup brewer and extend your machine's life. It only takes two simple steps. Single-use kit include a descaler and 0.25 oz. cleaning cup. Descaling liquid removes limescale from the heating elements to ensure proper brewing temperature is achieved. Cleaning cup ensures that the oily residue will be removed from the exit spout, which if left uncleaned, can cause bitter-tasting coffee. Maintain your brewer by descaling every three months, or more often if you live in an area with hard water. Cleaning cups can be used weekly, or as needed when switching between sweetened beverages and coffee and tea.