I tried to install my new Wyze floodlight today. My outdoor floodlight is mounted to a surface mount 4" round junction box. The Wyze floodlight has a bigger base diameter, about 5" so it doesn’t mate properly to the junction box. Nest floodlights come with an adapter plate but no such adapter is included with the Wyze floodlight. Major problem! I can’t find a 5" junction box for sale so I don’t think the Wyze floodlight is usable with a surface mount box. Think I will have to return it unless someone has another idea for mounting.
I also noticed the same problem. I’m thinking they only thought about it being flushed mounted. I am going to try to modify my 4" box by cutting about a 1/4" off the threaded inserts. So the mounting bar sits lower, then the flood light will sit flush on the 4" box. Between the floodlight and the 4" box I will use a gasket
Rather than a gasket, I used outdoor caulking cord (happened to be the Mortite brand) to seal the gap between the existing junction box and the floodlight case. With this, you don’t need to modify the junction box at all. Leave a small gap at the bottom (where the floodlight case has a notch) to let any condensation drain out.