4-inch octagonal ceiling fan support box, made of high-strength galvanized steel for enhanced durability and load-bearing capacity; specifically designed to securely support ceiling fans or heavy light fixtures, it features reinforced mounting points and a robust structure that ensures a safe, stable installation on ceiling joists, making it ideal for residential or commercial applications requiring reliable overhead fixture support. 4" Octagon ceiling fan support box Size: 4" x 4" x 2-1/8" Made of galvanized steel Max weight 70 lbs for fans, 200 lbs for chandeliers