IPEX Kraloy PVC Molded Octagon Box, 1/2 In. or 3/4 In. Outlet - Anderson Lumber
4 in. Octagon Fan & Fixture Support Box 2-1/8 in. — Primus Cable
Hubbell Raco 4 in. Octagon Box, Drawn, 1-1/2 in. Deep, Two 1/2 & Six 3/4 in. KO's, Raised Ground, Gray, (126): Electrical Boxes: Amazon.com: Tools & Home Improvement
Steel City 4 in. Octagon Box with 1/2 in. Knockouts 5415112-30R - The Home Depot