Bugulate BF35 Long Life Replacement Bulb (8,000 Hours) for Flowtron BK-15C, BK-15D, BK-2000, BK-CCN Bug Zapper (BF-35 15w Black Light)These long life bulbs are about 7½ inches long, good for small bug zappers with 1/2 acre coverage. They're great replacements for the Flowtron BF-35 bulb, and fit in several bug zapper models:. Flowtron BK-15, BK-15C, BK-15D, BK-2000, and BK-CCN bug zappers Galaxie GL-1450, GL-2050, and the GL-3515 Bug Fighter PM-1500, the PM-2000, and the PM-2015. If you're not sure whether these bulbs will fit, just measure your old bulb! Our bulbs measure 7.6' long (maximum of 7.9', including the connection pins) x 1.8' x 1'. The pins at the end of the bulb are arranged in a rectangle, 3/8' on one side and just over 1/4' on the other.The bulbs are designed to emit black light at 368nm, catching insects' eyes and drawing them away from you and into your trap.Resolving the occasional problemIf your shiny new BF-35 replacement bulb doesn't light up within 60 seconds, just plug something small (like a night light) into your outlet or extension cord to see if you have power to your bug zapper. No fancy test equipment is required!Most outdoor outlets are GFCI protected, and won't provide power if the circuit has tripped. You'll often see this type of outlet in the bathroom, where at least one outlet has small 'Test' and 'Reset' buttons. Any conventional outlet which is wired after a GFCI outlet in a circuit will also be protected by that GFCI outlet, so even outlets that appear 'normal' will be dead if the upstream GFCI outlet has tripped.Lastly, make sure any switch controlling the outlet is turned 'On'.Still won't work?If the night light works as you'd expect but the bulb doesn't, please check to ensure all four prongs of the bulb are seated properly in the socket.