Fernco 3" Qwik Cap. It is a flexible PVC cap that can be used to cap a pipe end, cleanout or open test pipe in a DWV system. It has a convex face design that helps ensure that it will withstand high levels of pressure for testing purposes and minimizes ballooning. This reusable cap is suitable for both aboveground and underground use on cast-iron, steel, copper or plastic piping. It is corrosion resistant, flexible, Lead-Free, removable, UV resistant, underground rated and has a maximum working temperature of 120°F.