Ideal Protection Set: you will receive a set that includes 4 inch vent cover and an outdoor bird guard suitable for 3'' to 4'' vents; Additionally, 14 screws are provided for easy installation Efficient Ventilation Design: the louvered design of the air vent cover allows for smooth airflow, while preventing lint or debris buildup and blockage; And, the bird guard keeps small animals out of the dryer vent while maintaining air circulation Durable Construction: our vent kit is made from quality plastic and rustproof galvanized steel, reliable and corrosion resistance, ensuring your outdoor exterior dryer vent cover can remain reliable over time, meeting your ventilation needs Easy Installation: this outside vent cover is compatible with various standard dryer systems, and the bird guard only needs to be placed over the vent cover and secured with the provided screws, no special tools are required Reliable Protection: this dryer vent cover and dryer vent bird guard set is designed to keep wind, rain and snow from entering outdoor dryer vents, which can ensure stable performance, extending the lifespan of your dryer system