The Flowtron Replacement UV Bulb is your friend during a crisis. The UV Bulb is essentially the heart of the Bug Zapper as it is the main method of attracting mosquitoes and other insects. In case you need to replace your UV bulb, this replacement UV bulb will be there to save the day (and night) for you and your family. This is a 2-Pack, which is cheaper than buying two separate bulbs for products which use more than one bulb. The Flowtron BF-150 Replacement UV Bulb is compatible with Flowtron BK-80 (2 bulbs), MC-9000 (3 bulbs), FC-4400, FC-4800 (2 bulbs), FC-4700 (2 bulbs), FC-7600 (2 bulbs).