The O-ring, code 06.56936-3104.0, is a compact yet highly effective sealing component used throughout the MAN L21/31 engine to ensure leak-free connections between critical interfaces. Designed with a precisely defined elastic profile, it compresses within its groove to provide a reliable barrier against the escape of fluids and the ingress of contaminants under varying pressure and temperature conditions. Manufactured from high-performance elastomer materials resistant to heat, oil, and chemical exposure, the O-ring maintains long-term flexibility and sealing integrity. Its dependable performance helps protect internal systems, reduce maintenance requirements, and support the safe and efficient operation of marine and stationary diesel engines.