Create a striking light display with these C9 light size retrofit replacement bulbs are slow color changing. You can see all the colors of the rainbow with thes slow changing bulbs. They are faceted LED screw-in replacement bulbs designed for traditional incandescent C9 (E17 socket) sockets. They have a 2 inch diameter. Each has 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,.6 watts per bulb. These are great for simple on/off applications. Not recommended for dimming (as in some computer animated displays). Sold in packs of 25 bulbs.