My pool light burned out in August of 2011, three days after the earthquake we had here in the East. Apparently many pool owners in our area had this happen, too. Pool light bulbs are very heavy duty (the filament is thick like a guitar string), but the earthquake was too much for many of them (understandably). This bulb worked perfectly as a replacement in my pool.One word of caution - replacing your pool bulb can be quite difficult, depending on your housing. Go to YouTube and look for some of the videos there on how to replace them. If you have trouble - be prepared to pay a pool service person to replace it. In my case, I needed about 45 minutes and a scuba mask to get the job done. Be SURE to get the light sealed properly when you reassemble it.