The Emerson FFS561L is a 4″ octagonal ceiling fan box with a 1-1/2″ diameter. This model is new in the box and designed specifically for industrial use. Emerson is a trusted brand known for producing high-quality electrical equipment and supplies. The FFS561L fan box is a reliable and durable component for ceiling fans, ensuring smooth and efficient operation in various industrial settings. For fans up to 35 LBS and fixture loads up to 70 LBS