The AUPU AV11A1 Ventilating Fan is a powerful and efficient fan designed for Bathroom/Utility Room use. With a 4 inch diameter duct size, it ensures optimal ventilation in small spaces. This fan from AUPU features one speed setting, providing consistent airflow of 110 cubic feet per minute (CFM) with an efficacy of 4.4 CFM/Watt. Equipped with advanced noise reduction technology, this fan operates at a quiet sound level of 1.1 sones, creating a peaceful environment in your bathroom or utility room. Although it does not have built-in lighting functionality, its sleek design seamlessly blends into any space without compromising on performance. This model was introduced to the market on July 10th, 2018 and has gained popularity due to its reliability and durability. It offers exceptional air circulation capabilities while maintaining energy efficiency. Please note that additional information such as power factor, light output lumens, life source life hours, total input power