To clean and restore discolored, dark grey teak and hardwood, this water-based formula is not only a high concentration cleaner, but it also contains brightener ingredients, which bring back the original color of new teak/hardwood. Most of the competitive brands require a 2-step-process: a separate cleaner and brightener. This creates twice as much work for the consumer. An extra advantage: unlike most of the other teak cleaners, ours is classified as non-hazardous.