One layer thick.
5.2mm radius
Here’s a screen shot from a SW model. This was before OS and BS had Mouse Ear support. I modeled the Mouse Ear and Shrew (spelling?) in SolidWorks.
Here’s a video that helped. I think there’s one from Slant3D also.
I’ll connect the mouse ears directly to the part if it’s large and I’m not concerned about seeing the circular pattern on my bottom surface.