The Nol-Tec 61436 Bottom Aeration Membrane is a high-quality 12″ ring gasket made of durable urethane material. This mini-jet aeration membrane is designed for use in industrial applications and is manufactured in the United States by the reputable brand Nol-Tec. With its unit quantity being one, this product is a reliable and efficient solution for improving hydraulic, pneumatic, and plumbing systems in various industries.