Help keep bugs at bay with this Flowtron ultraviolet replacement bulb. Use this efficient 40 watt bulb in your electronic insect killer to lure insects with invisible blacklight emissions. This replacement bulb is designed for use with the HH #5047-488 insect killer model #BK40CAN. Not ready for a replacement? The compact U shape of this ultraviolet bulb allows for easy storage, so you can always have a back-up bulb on hand when you need it. To keep your insect killer functioning effectively, replace the bulb every year.