Rust-Oleum Concrete Etch is designed to prepare bare concrete surfaces for coating, painting, or staining with ease and safety. Its citric-acid based formula works effectively both indoors and outdoors, opening tiny pores within the concrete to ensure maximum penetration and adhesion of coatings. This environmentally friendly solution is safe for grass and plants, making it an excellent choice for various projects. Additionally, it helps remove efflorescence, enhancing the surface quality. The product comes as a powder that mixes to create a 2-gallon solution, covering approximately 250 square feet, and is i for use with concrete coatings. Model Number: 238475