Salk Sani-Pant Pull-On Waterproof Cover-UpsNorthShore Item: 3626 Model: 850M
An updated version of old-fashioned plastic pants, Sani-Pant from Salk is vinyl coated polyester briefs. They are waterproof and feature soft cotton covered elastics in legs & waists. For sizing, if you're on the border between two sizes the smaller size is recommended.
From the NorthShore Blog