The mortice lock is activated by the door cylinder – it may be invisible but it has a crucial function. Just as it's impossible to start an engine without a starter motor, a door cannot be locked without a mortise lock.
ABUS offers a wide range of mortise locks that meet DIN 18251 with solutions for a variety of needs, e.g. fire doors or doors with narrow profiles. The premium product is the TKZ 40 – a self-locking mortice with an anti-panic function. This makes it possible to open the locked door from inside even if the key is not at hand.