safety feature

Usually it is a concrete thing (e.g. fitted to an electrical or mechanical device).

This is a very common term that's used frequently across diverse contexts, therefore it could refer to many different things - airbags and sidebars in cars, fire extinguishing systems, gas leak detection, laboratory safety systems, .., etc.. The collection of possible interpretations for this term vary as varies the context where it's being used.

To me, it's obviously more on the abstract

SurferTo me, it's obviously more on the abstract side.

Well, I guess the concept of safety is an abstract one, but the actual "safety feature" is normally a physical design feature or physical device. That's what I meant.