This class leading fan features three adjustable rotation speeds that can be set for silent operation or maximum airflow depending on your needs. At the quietest setting it rotates at 1500 rpm and produces an excellent 72.45 CFM at a virtually silent sound lover of 23 decibels. At the intermediate level of 2500 rpm it delivers an outstanding 115.75 CFM at a sound level of 30 decibels, which again, is very quiet. At its highest setting of 3500 rpm, this fan is able to produce an astounding 154.53 CFM while maintaining sound level of just 38 decibels. With a setting for every need and a reasonable price, you simply cannot go wrong with choosing this fan.