This is "Industrial Grade", made for contractors. A different lower concentration is made for DIYers at a lower price.
Gutter Zap cleans the black streaks off factory-painted metal and fiberglass - like gutters, RVs, etc - caused by electrostatic bonding.
Works best on factory-painted surfaces that are dry. Simply spray on, allow to sit for as little as 30 seconds, and rinse off with garden hose pressure. As soon as you see the black marks "move" begin rinsing immediately. Alternate method: wet rag with Gutter Zap (or wet MarXoff Brush) and wipe on. Allow to sit for as little as 30 seconds, and rinse off. Do not allow marks to re-dry.
Will not harm vegetation or painted surfaces when used according to directions.
Super-concentrated form! Once diluted with water, makes 2-3 gallons of this amazing gutter cleaner. Each bottle cleans up to 500 feet of gutters.
Save money! Buy a 6-Pack and get the sixth bottle FREE!
"Gutter Zap did a remarkable job! The gutters looked brand new by the time I finished. They went from striped and grey to completely white. Thanks again." Justin K., Tennessee