The Freudenberg-NOK 3.975" 90 HNBR O-Ring is designed for optimal sealing performance in challenging environments. Constructed from high-quality HNBR, this O-ring is resistant to heat, oil, and chemicals, making it ideal for various industrial applications. With a diameter of 0.210" and a hardness of 90, it provides a reliable seal under pressure. This O-ring adheres to industry standards, ensuring durability and performance in hydraulic and pneumatic systems. Its precise sizing guarantees compatibility across multiple applications, making it a vital component for effective sealing.