This Valterra plumbing vent Bug Screen is sold individually. Screens must be inspected monthly and cleaned when necessary to maintain proper air flow.• Fits four prong type RV roof plumbing vents• Easy-to-install screens• Minimal airflow restriction• Ensures that your vents stay free from costly invasion by unwanted pests (nesting insects, birds and rodents)• Heavy duty stainless steel mesh cover• Screen measures 2.47" diameterSpecs: Appliance Type: PlumbingQuantity: SingleCompatibility: 4-Prong Roof VentsMaterial: Stainless SteelWith Mounting Hardware: Yes Minimal Airflow Restriction Ensures That Your Vents Stay Free From Costly Invasion By Unwanted Pests Easy-To-Install Screen | Valterra RV Bug Screen for RV Plumbing Vents