This dome light uses a 1 quart Mason jar with a 3" mouth to protect a 13-watt 120 VAC fluorescent bulb that gives as much light as a 60-watt incandescent bulb. A 23 watt fluorescent bulb (100 watt equivalent) will also fit into the jar. Jar lid and ring are screwed to wall, lamp socket, too, and wires pass thru wall to socket. Mine is 120VAC wired to 130-watt inverter, but 12 VDC fluorescent bulbs are available in Wal-Mart camping section. Lots of light, durable glass protector, and a great price!