Low-level policy urdf choice

[wzx16]

Hi, thanks for sharing this amazing project. I found in the low-level policy folder there is a b1z1.urdf and a b1z1-new.urdf, inside which some of the parameters are different. I found if I load b1z1.urdf to isaac-sim, the structure of the z1 arm is incorrect as the following images:

This issue doesn't exist in b1z1-new.urdf. However, I found the low-level policy use b1z1.urdf instead. Could you kindly explain the difference and give some choice suggestions? Thank you!