unet = UNet2DModel.from_pretrained("google/ddpm-cifar10-32", use_safetensors=True)
```  
To load and save model variants, specify the `variant` argument in [`ModelMixin.from_pretrained`] and [`ModelMixin.save_pretrained`].  
```python
from diffusers import UNet2DConditionModel

unet = UNet2DConditionModel.from_pretrained(
"stable-diffusion-v1-5/stable-diffusion-v1-5", subfolder="unet", variant="non_ema", use_safetensors=True
)
unet.save_pretrained("./local-unet", variant="non_ema")
```