Discs With Domes For Learning Delays

I am totally green to this sport and looking at the Pros Freestylin’ & Jammin’ a disc like as if the disc is stuck to their fingers is amazing!!!
I have came across instructional sites that have briefly mentioned about freestyling discs having sort of a "ring" in the center on the underside of the disc for better guidance while Spinning.

How true is this? If true, which manufacturer/model of disc has this?

As I am very new to this, I would think this might help me learn to spin at the beginner’s level.

Please help!