Available to fit 2, 3, and 4 in. diameter commercial building plumbing vent stacks and restaurant grease interceptor vents, SureSeal® Vent-Guard eliminates toxic sewer gas and odor egress and migration to nearby rooftop HVAC system air intakes. Maintenance-free product is constructed of EPDM rubber that withstands temperatures from -50 to 150°F. Design uses non-mechanical hinged flapper that allows airflow in while eliminating infiltration of insects, animals, and inclement weather.