The mirror tool, located in the layout workspace lets you mirror a model and all the features associated, supports, holes, hollowing, hollow blockers, rafts…
Click on the tool icon to launch it, or M on your keyboard.
Once you have an active selection, click on one of the colored cones to mirror the X, Y, or Z axis. You can use one of the 3 buttons in the tool option at the bottom of the screen.
Tips: The mirror is now based on the world axis.