Wasps, mud daubers, birds and rodents pose a serious threat to the plumbing system on your RV. They can enter through the plumbing vents and cause serious damage by building nests that interfere with air flow. Camco 42152 (Model PL 100) fits four prong roof plumbing vents. This easy to install screen will help ensure that your vents stay free from costly invasion by unwanted pests.