They are faceted LED screw-in replacement bulbs designed for traditional incandescent G40 (E26 socket) sockets. Each has ten super bright LEDs encapsulated by a hard-to-break lens (unlike the old-fashioned and very fragile incandescent bulbs). Fits directly into existing traditional sockets without extra transformers. Saves a considerable amount of power on electric use. These are fine for simple on/off applications. Not recommended for dimming (as in some computer animated displays).