Deflecto Universal Bird Guard Dryer Vent Cover, For Use with 4 Inches Clothes Dryer Vents, Brown (UBGBB) Easy to install, for use with 4" clothes dryer vents or 3" bathroom exhaust vents Helps prevent birds from nesting in vents and rodents from entering through vents Durable and weather-resistant with UV inhibitor added to hood to prevent sun damage and cracking Check periodically and remove lint or other debris, if present Melting point: 325F / 163C