MasterCare® PRO-YELLOW is a powerful cleaner ideal for condensers, micro-channels, and mini-splits that targets large concentrations of dirt and grime. With its heavy foaming alkaline-based solution, debris will be removed from the coil while providing excellent brightening. 1 gallon makes 4 gallons of coil cleaner. Diversitech Pro-Yellow™ Coil Cleaner, Non-Toxic, 1 gal, Liquid, Odorless, Composition: Water, Sodium Hydroxide, 1.15 Specific Gravity, Yellow