The DIN 2353 plug, type VSTI-ME for hex key, is designed with an external metric thread and sealing in accordance with DIN 3852 type E, using a high-quality elastomer gasket with a rectangular cross-section to ensure reliable tightness. Engineered with a robust 4:1 safety factor, it guarantees dependable performance even under demanding operating conditions. Manufactured from durable carbon steel and finished with a zinc-nickel coating of 6–10 µm thickness, the plug offers outstanding protection against wear and corrosion, achieving resistance of up to 720 hours in a salt spray chamber. This advanced surface treatment not only extends service life but also ensures consistent functionality in harsh environments, making it an ideal solution for hydraulic and pneumatic systems where durability, safety, and long-term reliability are essential.