Steel City® 54151CFB-BHL Octagon Ceiling Fan Box, Steel, 15.8 cu-in Capacity, 1 Outlet, 3 Knockouts, 1-1/2 in D Dimensions | SMC
926 Ceiling Fan Box w/Brace, 1-1/2-inch Deep Octagon box, for Ne.-Ceiling fan brace-Ceiling fan support-Ceiling fan box-Ceiling fan mounting - Walmart.com
BELL PRCF57550BZ Ceiling Fan Electrical Box, Bronze, 4.75 in. - Amazon.com
Hubbell-Raco 294 2-1/8-Inch Deep, 1/2-Inch Side Knockouts, Wood Joist Bracket 4-Inch Octagon Ceiling Fan Support Box Gray - Electrical Boxes - Amazon.com
how to install the mounting bracket for ceiling fan - Home Improvement Stack Exchange
Legrand Pass & Seymour Slater New Work Plastic 4 In. Round 20.25 Cu. In. Premium Grade Fixture & Fan Ceiling Box S120JFAN - The Home Depot
Westinghouse Lighting 0124000 Sidemount Plus Fan Box, 2-1/8 Inch Deep Gray - Chandeliers - Amazon.com
Carlon B720R-SHK - 20 CU. Inch Ceiling Fan Box - Deep