Made of heavy black rubber with a semi-solid inner lining for easy insertion and an adjustable valve pump to inflate and lock at different widths. Easy to keep clean with warm soapy water. Thank you Submitted by Fred G. I would get so stressed I would be constipated for days. The procedure won't hurt your dog, but if the glands are particularly swollen or impacted, your pet might be guarding their backside more than usual. Julie, saw your comment and I am in the same boat.