The rigid shaft connectors in motorised roller shutters are used instead of standard suspension springs. They get clipped or fastened on the shaft. By this the pushing up of the shutter becomes very difficult.

1.) The obstacle detection function of the electronical tubular motors is ensured.
2.) Lifting up the shutter from outside the house becomes almost impossible.
     The protection against burglary is appreciable higher.

„„Securing windows with conventional roller shutter systems is insufficient! Usual roller shutter systems do not have an anti-burglary effect and are mainly used for privacy and for shade matters. Nevertheless there should be a protection with additional, mechanical rigid shaft connectors, to prevent any push-up of the roller shutter from the outside.”

(Source: https://www.einbruchschutz.polizei-beratung.de/rolllaeden)