None No Pest Vent 4 in. J Block or Wide-Mount Dual Door Wall Vent in White

The No-Pest Vent keeps pests out of exhaust vents, saves energy and is practically maintenance free. Its unique, dual door design prevents birds, mice, and other pests from entering the vent. The outer door creates a vortex effect, drawing additional external air to provide more door lift and flush lint away. This is the highest air flow, cleanest operating vent available.