With the most comprehensive line-up of compression joint sealers, Fernco Donuts are known for creating a strong and lasting joint. Our flexible-PVC rings are an industry staple for the sealing of sewer pipe joints and DWV connections such as sockets, hubs, bells and spigots. Unlike other manufacturers, Fernco Donuts are available in hundreds of sizes and configurations for use with most brands and types of piping material. Fernco Donuts are called on to seal against infiltration, connect material-to-material or material transitions, and adapt size-to-size or increased sized pipes.