civitai.com/models/591219

A posture collar based on the SD1.5 model from https://civitai.com/models/18800/posture-collar . Seems to work fine but you might need to add some detail or texturing back as the 1.5 base will simplify the image a bit otherwise.

Can be used at lower weights to generate wider/thicker collars than the default ones in Pony/Illustrious.

Recommended strength 1