We put together this quality metal clamp light with our 11 Watt CFL bulb. This is the best in compact fluorescent DC lighting. The lamp has the light output equal to a 40-watt incandescent bulb. Average life span is 6000 hrs. This bulb is not sensitive at all to many on/off cycles. Plugs into standard female car light socket or into the DC socket on our Xantrex Power Packs.