Hello.
Stupid question - how do you actually mount cAP 2n on the wall/ceiling? Before I ordered it, it looked straightforward (or at least that it would be intuitive) from the pictures but now that I have it my hands I can’t, for the life of me, figure it out.
I know you can latch the square “Ceiling mount attachment” into the back of the device and mount it to the wall/ceiling but then what’s the round one for? 
Ok… nevermind… I figured it out… I think… 
If you have a dropped ceiling or drywall you want to attach the device to, the round bit goes on the other side of the ceiling tile/drywall to provide better support for hanging the device.
Do you have pictures as a guide? I’m about to install 5 of these this week for the first time and I thought it would be good to have some practice. My guess is that it’s just a marker really and spreads the load further across the ceiling tile right? For drywall you shouldn’t need it though. Thoughts?
I’m attaching a crude diagram I made of how I think it should go. I can’t be sure though. The round bracket would be just for support on the flimsy ceiling tiles.
The screw holes in the round bracket are threaded and you get 2 long bolts in the package. The screw holes in the rectangle bracket match up perfectly with the screw holes in the round one so I guess they should be screwed together.
You could use it with drywall just for the extra support, but you would need to have access to the other side of the drywall, or put it on the drywall sheet before screwing the sheet to the wall.