Specifically designed for locking doors along escape routes. As an additional locking mechanism, it is also suitable for applications in fire doors. The secure unlocking under preload (max. 5000 N) makes it particularly suitable for doors with escape route requirements. In sluice systems, soundproof doors, and doors where pressure on the door latch is expected, the 331U series ensures reliable operation.

Resistance to forced entry: 5000 N (Fafix version) without strike plate.