Review on 🔌 Westinghouse Lighting 0105000 Saf-T-Box: Secure and Spacious Electrical Junction Box, 1-1/2 Inch Deep, Silver - 15.5 cu-in, 3.62 in L x 3.62 in W by Issac Smart

This is the most powerful ceiling fan available (rated at over 100 pounds). Installation requires access to the attic. It has plenty of room for cables (1-1/2 inches deep), built-in cable clamps, and uses solid threaded steel inserts that are riveted to the back of the box to mount the fan. Installation takes a little longer since the box isn't round (requires using a drywall saw to cut a hole). Otherwise, I find these boxes take just as long to install as more expensive modified boxes with an expandable bracket. The trick is there to cut a hole, insert a crate from the attic side and install the 2x4 between the ceiling joists, using temporary 1" spacers between the 2x4 and the drywall to ensure the spacing is correct.