Rust-Oleum Zinsser Flat White Cover Stain Interior/Exterior Primer, 1 gallon is a versatile primer designed for both interior and exterior surfaces. This flat white primer provides excellent coverage and stain-blocking properties, ensuring a smooth and durable base for your paint projects. I for use on a variety of surfaces, it helps to seal porous materials and prevent stains from bleeding through your topcoat. Whether you are tackling a renovation or a new paint job, this primer enhances paint adhesion and improves the overall finish, making your paint job last longer and look better. Model Number: