The O-ring, code 06.56936-2985.0, is a compact but essential sealing element used throughout the MAN L21/31 engine to ensure leak-free connections between mating components. Designed with a precisely defined elastic profile, the O-ring compresses within its groove to create a reliable seal against fluids and gases under varying pressure and temperature conditions. Manufactured from high-quality elastomer materials resistant to heat, oils, and chemical exposure, it maintains its flexibility and sealing capability over long operating periods. By preventing the escape of lubricants or coolant and protecting systems from contamination, this simple yet highly effective component contributes significantly to the operational safety and efficiency of marine and stationary diesel engines.