Units used for near_plane and far_plane limits in nerfacto model params.

[karun2016]

What is the unit of measurement used in nerfacto model paramaters for training?
I see the following deault values and what implications are those values in collider_params vs ones below that?
model=NerfactoModelConfig(
_target=<class 'nerfstudio.models.nerfacto.NerfactoModel'>,
enable_collider=True,
collider_params={'near_plane': 2.0, 'far_plane': 6.0},
near_plane=0.05,
far_plane=1000.0,
---
)