The Freudenberg-NOK Z7257 O-Ring, compliant with AS568-345 standards, features an inner diameter of 4" and an outer diameter of 4-3/8", with a cross-section of 3/16". This O-Ring is engineered from high-performance materials, ensuring excellent sealing in hydraulic and pneumatic applications. Its robust design provides superior resistance to oils, fuels, and chemicals, making it suitable for various industrial environments. The Z7257 is a reliable choice for engineers seeking a compliant and durable sealing solution.