Our Series FS4000 O-Rings for ORFS (O-Ring Face Seal) adapters are made from durable Buna-N Nitrile (NBR) material with a 90-Durometer hardness, designed for optimal sealing in hydraulic and pneumatic applications. These high-quality O-rings are engineered to provide leak-free connections in ORFS fittings, ensuring secure, tight seals for fluid and gas transfer. The Buna-N Nitrile (NBR) material offers excellent resistance to oils, fuels, and other industrial chemicals, making it ideal for use in demanding environments. With their superior sealing performance and reliability, these O-rings help maintain the efficiency and safety of fluid power systems.