For doors without a lock, where a strike is to be applied, a counterpart built into the door leaf, a so called mechanical latch bolt is to be used.

Flush (mortise) mounting version.
Mortise latch bolt locks of model series 807 are tested in accordance with applicable regulations and are approved as suitable mating components for electrical locking systems in doors along escape routes.
The latch bolt is adjustable from 12 to 17 mm (projection). This means that it can be adapted to the door gap on site thus ensuring actuation of the monitoring contact.