Protect your home with The Crown VentGuard!The waste system in your home requires full air flow through the roof vent. If your roof venting system is clogged, your plumbing system will not work properly. Sinks, toilets and showers will not drain correctly. Your home may fill with very unpleasant odors!Note: Fits 3″ PVC roof stacks. PVC reducer coupling required for smaller stacks.