How to Install a Dryer Vent (DIYer's Guide) - Bob Vila
What is this second hole that is connected to dryer vent? The open one and the one connected to tubing are the same duct and run up to roof vent. No blockage
Here's the correct way to vent your clothes dryer - The Washington Post
Amazon.com: Dundas Jafine TDIDVKZW Indoor Dryer Vent Kit with 4-Inch by 5-Foot Proflex Duct, 4 Inch, White : Appliances