How to mirror an object (reverse its sides)?

I’ve built a 3D model that is to be used in an application where it is projected on a mirror. This model will be viewed from the mirror so I need a way (a function) to mirror the object in Unity so that when it is projected on the mirror it will look in its proper orientation.

You could just set its transform’s X scale to -1, and rotate it accordingly.

How would one do this with a prefab hierarchy that’s the child of a empty game object?

Thanks mate, you still saving lifes hhhhh