High security in great conditions key protection: patent and trademark protection number of locking elements: 6 patent term: 2034 special feature: intop system test unit in the key and cylinder, which prevents locking with an unauthorized key, to increase the manipulation protection, additional profile rib with interrogation pin note: cylinder prices do not include their keys. This publication is ideal for readers seeking insightful and educational content. Prepared by experienced authors and printed with high-quality materials. Great for students, educators, and curious minds.