Star brite Mold Stain & Mildew Stain Remover + Cleaner High-Alkaline, Triple-Action Formula Works Instantly. Mildew stain remover quickly removes unsightly mildew stains from fiberglass, vinyl, plastic or painted surfaces. It begins working on contact. The special buffered formula will not harm vinyl upholstery or threads. It is a much safer alternative to using bleach, and can also be used around the home or in RVs wherever mildew stains are a problem.Star brite Mold Stain & Mildew Stain Remover + Cleaner High-Alkaline 22ozQuickly removes stains caused by mold & mildew on contact without heavy scrubbing; EASY TO USE spray, wait until the stain disappears, then rinseSTAIN REMOVER + CLEANER: High-alkaline, triple-action formula contains; BUFFERED-BLEACH to remove mold stains & mildew stains; CHELATING AGENTS to lift ground-in dirt; SURFACTANTS to cut grease & grimeBUFFERED-BLEACH TECHNOLOGY is better suited for marine/outdoor upholstery and outdoor acrylic fabrics including Sunbrella; Wont harm stitching or threadsMore effective cleaning power than unbuffered bleach-water based products, or diluted supermarket brandsWorks on; awnings, fiberglass, wood, concrete, drywall, siding, tile & grout, gutters, roofs, vinyl upholstery, most outdoor acrylic fabrics, and more *(test fabric for colorfastness before use)Professional-strength, concentrated formula for boats, homes, RVs, and commercial useStar brite products are proudly made in the USA since 1973