Żarówka reflektora and other 65,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
This is a lightbulb icon. It is shaped like a funnel, with a very wide end at the top then it tapers off towards the bottom. At the bottom, there's a very small black part which is the part that attaches into the fixture.