Oatey Knock-Out 4" Vent Caps. Knock-Out Test/Vent Caps feature a deep design that provides a strong, leak-free connection. The center of the test cap can be "knocked-out" (hence the name) and removed utilizing the "tab" feature to prevent possible blockage in piping. In the REO or Property Preservation industry, these vent caps are ideal for capping dryer vents to prevent cold air and critters from getting into properties. They can also be sued to cap 4" PVC drain lines typically found under toilets. 

Features

• Knock-out center
• Pull tab for center

Specifications

• 4" width x 0.75" height