They're sold here and used for places like kitchens, some table lamps....etc.
It is essntially a version of compact fluorescent lamp. Probably better since when the ring goes out, all you do is replace the ring, not the ballast.
Some years back I installed a screw-in ceiling bulb fixture in my mom's kitchen to replace the non-working fluorecent fixture (this was on a weekend and was all I had available and all I could afford at the time). I screwed one of these fluorescent rings into it.
Some time last year, during one of their inspections, the housing authority came and replaced it with a proper fluorescent lamp.
