The closing cover, code 11.01288-0075.B, is a key sealing and protection component designed to safeguard the internal spaces of the MAN L21/31 engine from external contamination and lubricant loss. Precisely machined for a perfect fit, it provides pressure resistance, structural rigidity, and effective sealing at designated housing openings and inspection points. In addition to preventing the ingress of dirt, moisture, and salt particles, the cover contributes to improved thermal stability and reduced noise emissions, supporting a controlled and clean internal environment. Its robust construction and corrosion-resistant surface treatment ensure long service life, making it an essential element for reliable engine performance and optimized maintenance intervals in demanding marine and energy applications.