Product Description Increase the air circulation in your Rion EcoGrow with an additional air vent. Additional air vents will aid in reducing humidity levels, and improve air circulation to keep your greenhouse cooler on warm days. This is an Extra Choice product. Please see the Extra Choice information within customer services for more details. Provides additional air ventilation. Helps regulate temperatures. Works with all Rion eco-grow greenhouses. Can be fitted with the Palram automatic roof vent opener for optimal airflow.