Sonos Sloped Ceiling Speaker Mount

I'm planning a surround sound area in a new game room to use Sonos playbar and speakers.
 
For the rear channels I would need to suspend the speakers from a sloped ceiling (ceiling peaks in the middle slopes to left and right).
 
Does anyone know of of ceiling speaker mounts that will work on sloped ceilings?
 
I've searched a decent amount and have not found such a thing.
 
Thanks for any and all suggestions.

Here's one option: https://www.monoprice.com/product?c_id=108&cp_id=10828&cs_id=1082804&p_id=6980&seq=1&format=2 (under $4 for a set of 2)

Thanks for the link. I'm really looking for more something like this:
 
https://www.amazon.com/Flexson-Ceiling-Mount-Sonos-Play/dp/B00NEPBMZA
 
I may get the Flexson mounts and make a wooden wedge to mount under it to adapt the slope.

Flexson quality is good normally.
Placed a Cavus play:1 mount last week, but lot's of plastic...