The protecting cap, code 11.01251-0048.0, is a small but highly important component in the MAN L21/31 engine, designed to shield sensitive connection points and fasteners from contamination, moisture, and mechanical damage. By sealing exposed interfaces, it helps prevent corrosion and the ingress of dirt or salt particles, which is especially critical in marine and offshore environments. Its durable construction ensures long service life and supports cleaner, safer maintenance procedures, contributing to the overall reliability and operational integrity of the engine.