A shutter latch is a sliding pin that locks the lowered shutter so it cannot be raised from outside. It may engage in the guide rail, the frame, the sill or the wall.
There are many kinds: manual pins that you slide across from inside, pieces that lock automatically as the shutter comes down, and bolts that go into the floor. What changes between them is where they hold the shutter and how many points they have.
In our shutter security system, the latches go at both ends of the bottom slat and lock into the wall. Together with the 4 mm steel T-profile fixed to the slat, which does not bend, they mean the shutter cannot be lifted or bent.