This is a genuine Claas 7700011030 M16 self-locking hexagon nut, designed for secure fastening in demanding agricultural applications. Featuring an M16 thread and a 24mm wrench size, this high-strength steel nut ensures reliable performance across a wide range of Claas machines, including models from the ARION, AXION, LEXION, JAGUAR, and XERION series. Its self-locking mechanism prevents loosening due to vibration, enhancing operational safety and longevity.