These heavy-duty rubber expansion plugs are built with a non-corrosive design using high-quality rubber, durable nylon, and stainless steel components for long-lasting performance. The easy-turn wing nut tightens smoothly and delivers up to 50% greater sealing power than conventional expansion plugs, ensuring a secure, leak-free fit. Ideal for a wide range of applications including home plumbing repairs, pipe testing, leak prevention, and swimming pool winterizing. Each plug features a convenient blow-through fitting, making it easy to blow out lines or prepare pipes for winterization. A reliable, all-purpose solution for DIYers and professionals alike.