I have seen a brass coffin locked with chains. I want to know why. There won't be zombies, will there

1. The copper coffin is sealed. It is difficult to prevent the antiquities (including corpses) in coffins from weathering after being exposed to the air. It is best to open it in a vacuum environment.

2, for safety, prevent organs, viruses, etc.

3, perhaps superstition or pseudoscience, to prevent the body from deteriorating or cursing.