An easy way to control holding tank odors and gassing, this chemical-based, head and holding tank treatment works without formaldehyde to control odor. Special additives keep holding tank walls and drain lines free from debris. Latest technology lubricants keep drain valves from sticking. Environmentally safe formula allows pump out at any dumping station. Safe and effective for all RV and marine toilets. Has a fresh mint scent. Four ounces treat a 20-gallon holding tank.