The 40-Watt, 12" U-Tube Replacement Lamp keeps your Flowtron Bug Killer running efficiently. Yearly replacement is recommended to retain maximum black light output, and with Flowtron"s comprehensive line of black light replacement bulbs, you can choose the perfect size and setting for your needs. This bulb is a 12-inch, 40-watt high intensity black light bulb, designed to work with the BK-40 model bug killer. All bulbs are easily replaced through the bottom of the unit with no disassembly required, so replacement is quick and easy. This replacement bulb provides maximum luring power, so you can tackle bugs with the power to win.