Octagon box, 3-1/2 in with four 1/2 in side conduit knockouts and one 1/2 in bottom conduit knockout. Drawn construction, can be used in the installation of ceiling or wall lighting fixtures or as a junction box. Not designed for ceiling fan support. 50 pound maximum recomended static load. UL 514-A listed, File E195978, acceptable for use in 2-hour fire rated walls. UPC bar code.