METAS, the Swiss Federal Institute of Metrology, is responsible for the Master Chronometer certification, which represents a high standard in watchmaking. This certification is a testament to a watch's precision, performance, and resistance to magnetic fields. To achieve METAS certification, a watch must first be COSC-certified, ensuring it meets the basic standards of chronometer accuracy. The METAS certification process involves a series of rigorous tests, including exposure to magnetic fields of 15,000 gauss, water resistance, and power reserve assessments. Additionally, the watch's accuracy is tested in various positions and temperatures, ensuring it maintains precision within 0/+5 seconds per day. This comprehensive testing guarantees that both the movement and the fully assembled watch meet the highest standards of reliability and performance. METAS certification is currently used by prestigious brands like Omega and Tudor, reflecting their commitment to producing timepieces that excel in both functionality and durability.