This ring light adapter clips onto the end of a Laowa 25mm macro lens.

The 12V ring light was purchased from Amazon as "Qasim 1 pair of LED COB Angel Eyes Halo Rings with Plastic Cover 80MM 3.15'' White 63SMD for Car Motor DRL Headlight Fog Light DC 12V"

The light has an outer diameter of 83mm and an inner diameter of 68mm. There are three tabs on the rear that clip into the slots in this adapter.

I have it powered by a 9V to 12V adaptor box that attaches to the camera's tripod mount; see my thing "Camera power pack (originally for a Laowa 25mm macro ring light)"