The Yale PM444 series security door bolts are concealed (mortice fixed) into the door with a bolt which throws into the door frame. Operated by using the key supplied giveing added securiy and extra protection to your home. The Yale YALPM444KB is 1 x Additional Key Only for PM444 Door Security Bolts. The additional key is ideal to store in a safe place in case of misplacement of the original key. https://elecena.pl/product/27145849/yale-locks-pm444kb-key-for-door-security-bolt 2024-11-06 https://elecena.pl/product/27145849/yale-locks-pm444kb-key-for-door-security-bolt 2025-03-06 https://elecena.pl/product/27145849/yale-locks-pm444kb-key-for-door-security-bolt 2025-03-17 https://elecena.pl/product/27145849/yale-locks-pm444kb-key-for-door-security-bolt 2025-03-28