This product looks good, feels good, and is very well made.
There are other types out there that are either cheap or more expensive. But this one fits nicely in between the two.

Although I have not had the chance to use it because of a change in the weather (don't you hate it when that happens, when you get new gear) I haven't used it with my QUARK and GPCAM3 290M. But looking at it. I know it will rid me of those vexing Newtons Rings we see when imaging in Ha.

bought this to eliminate interference pattern i was getting imaging the sun, had to apply a lot of tilt and still hasn't reduced the interference totally but can get rid of remaining pattern with flat fields, I noticed that with large degrees of tilt that light enters through the gap created by tilting so black electrical tape needs to be applied around the perimeter of the 2 rings

I have been using a ZWO ASI178 mono to do solar imaging and for whatever reason this camera suffers from very pronounced Newton rings. After careful adjustment this ZWO tilt plate removes the rings by tilting the camera sensor.. It works well.