Moontanner It SMA version, I attached a pic. 
We recommend starting with the default USB bandwidth settings. If everything is working smoothly, there's usually no need to change them.
The USB bandwidth setting determines how much USB transfer capacity the camera can use.. Generally, higher bandwidth can improve transfer speeds and frame rates, while lower bandwidth may help improve stability.
For ZWO cameras, we generally recommend keeping the USB bandwidth below 80% when using one camera, or around 40–50% per camera when using two. This can help maintain stable image transfers, especially when both cameras are operating simultaneously.
You can fine-tune the settings based on your setup to find the best balance between performance and stability.