POWERFUL FORMULA | Our fast-acting cleaning agents dissolve months of coffee residue and hard-water scaling to restore a fresh, clean taste. REMOVES STAINS | Prello lifts the brown film off of glass, metal, and ceramic so your travel mug, coffee pot, and cups look new. OPENS FILTERS AND SCREENS | Prello can clear away the buildup of oils and grit that block your permanent filters, allowing better water flow and more consistent brewing. EASY AND OBVIOUS | Prello isn’t just a pretty face; it has a custom blue color that lets you know that it’s working. When Prello turns green, it has dissolved away coffee stains and is ready for you to rinse it away! CLEANS THE WHOLE MACHINE | One bottle can clean the pipes and drains as well as the coffee pot and mugs.