Pro-Yellow™ is a powerful cleaner ideal for condensers, microchannels, 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. Pro-Yellow is biodegradable, NSF approved and available in a number of packaging solutions. Diversitech Pro-Yellow™ Coil Cleaner, Non-Toxic, 1 gal, Liquid, Odorless, Composition: Water, Sodium Hydroxide, 1.15 Specific Gravity, Yellow