It’s the official nudity-erased SD v1.4 UNet checkpoint from
https://erasing.baulab.info/weights/esd_models/NSFW/ and can be loaded via NSFW.pt") into a CompVis/stable-diffusion-v1-4 UNet.
Note:
The specific file you downloaded as NSFW.pt (diffusers-nudity-ESDu1-UNET.pt) is published as full UNet weights, so strict=False generally isn’t necessary; strict=True is preferable to catch “wrong base model” mistakes (e.g., loading SD-v1.4 weights into SDXL). is required.