If they burn out, contact the manufacturer for refund/replacement. Keep your receipt and send a copy. I have done it.
Karen wrote: I bought the spiral flourescent bulbs that were supposed to last years and had 5-6 of them blow out in the first year. Didn’t even last as long as most regular bulbs and cost so-o much more. BUT I was using them in fans!
Also, you can’t use them in several other things such as dusk to dawn, motion, and I’m not sure about dimmers. This has all been several years ago so hoping that soon they come out with some that can do all those things. Karen