This is a very early compact fluorescent bulb, or CFL. Unlike modern compact fluorescent bulbs, it has a full glass dome cover, and it has a tiny, old-fashioned starter bulb inside, instead of a modern electronic starter. This older design takes 2 whole seconds to light up, by design. It is also VERY heavy. So heavy in fact, that the box it came in warns that it "May cause instability of free standing lamps"! It came in an elegant cardboard box, unlike modern CFLs, which usually came enclosed in a vacuum-molded transparent plastic container. These days, even modern CFLs are going away now, replaced by LED light bulbs which are better in every way.